I have been going back and forth on each of these products sites and then thought id just ask here what people seem to be using and what they think.
Asking fellow Tr users what one they use and why they like it. Maybe this will bring a point together I had not thought of for using one over another.
Thanks for any help 
Much cheaper than a Fenix 5 (or 6), I have a Polar Vantage V watch (originally purchased to provide running power from the wrist). I use their companion heart rate chest strap for the orthostatic test upon waking most mornings, which I have found to be excellent. Plus I like Polarās Flow app.
They do have a detailed sleep analysis thing using the watch only (optical heart rate), but thatās a bit more questionable with respect to its precision in measuring the HRV.
Thatās my totally unscientific, anecdotal evidence. 
I have the Oura ring. Overall Iām reasonably happy with it, however it does have some limitations:
As far as sleep, HR, and HRV tracking go it seems to do a good job. I think its sleep tracking correlates better with how I think I have slept than my fitbit, although I havenāt done any close comparisons. The resting HR and HRV are highly correlated as I expect, but itās hard to know how accurate these really are.
My main goal of using this is to get HR/HRV data that I can use directly, and it gives me that. Their āreadinessā score seems mostly based on how you slept the prior night, and only slightly influenced by the HR/HRV, so I donāt put much stock in that, other than looking more closely at my numbers on those days.
I went with the Oura (on sale for Motherās day as it was much cheaper than the Whoop. I canāt get behind a $30/month subscription for this. My ring was $335 out the door, so cost was a big factor for me. From reading the details on Whoop it seems like even though it is a subscription, it is still structured as a HW purchase, so if it breaks you could have to ābuyā another one. Also no clear information on what access to the new hardware my subscription gave me. If Iām paying a subscription for HW, that needs to include guaranteed working, up-to-date hardware. The hardware is interesting, but their business model is not.
To be honest the one thing keeping me from whop a little bit is the subsrictpion
Just what I need another subscription lol
I like that whoop seems to give insight into lot more data but the one thing I want more then anything else is sleep info
Which it sounds is a big reason to go wit the ring
I went with the Whoop. Iāve had it about a month so far and Iām surprisingly happy with it. I went in pretty skeptical because I already had a new Apple Watch and was using the AutoSleep app. Iām not a good sleeper and my #1 goal was to improve there.
I REALLY like that the Whoop analyzes my daily strain and then recommends a daily sleep goal. It understands that if I go hard that day I need more sleep and if I had a very low stress day, I can get by with less. This has helped my change the way I think about my sleep. Iām not constantly stressed over how far behind I am and how I need to ārefill the bankā. If I had a low stress day, itās ok that I slept a little less. If I had a high stress day, I should go to bed a little earlier or maybe skip the sunrise group ride and do something solo after a few more hours rest.
Itās only been a month, but so far, I find that following its Strain and Sleep recommendations is working for me.
Iām confused about a daily sleep goal. I go to bed between 10 and 10.30 and go to sleep. I may sleep 5 6 or 7 hours but donāt seem to have any control over how long I sleep. Mostly I wake up early sometimes (not often) late. Am I missing something? If I go to bed earlier I wake up earlier.
You absolutely have control over how much you sleep. There are lots of books and techniques you can research if you donāt want to talk to a doctor. Sleep is the number one key to recovery.
I have not read it yet, but Iāve heard Nate recommend the book, āWhy We Sleepā. Search this forum for more posts and podcasts on sleep. Sweet dreams!
Just like @Pbase I went with the Whoop. Iāve had it a since August now and Iāve noticed recently that as Iāve built up a backlog of data on myself, the Recovery score much more closely aligns to how I feel getting out of bed. The first month it was kind of give or take but then I crossed this threshold where I could get out of bed and have a reasonable expectation of what my Whoop was going to say when my recovery had processed.
Most importantly for me, I can see what things cause my recovery to be lower the next day. Have a cocktail too late? Recovery is going to take a hit. Crush a hard threshold/VO2 ride late in the evening? Recovery goes down. Conversely, if I get no activity at all, my recovery goes down. Iām getting a much better sense of what things impact my ability to train both good and bad.
I can also tell when Iām going to have a killer workout - when my recovery is 90%+ I absolutely slaughter my workouts. Below 60%, itās a slog. Below 40%, dont even bother. This doesnāt seem to be weird confirmation bias either. I have, on several occasions, just done my workout without reviewing my recovery and then recorded my RPE post workout. Only then do I look at my recovery. 9 times out of 10 my RPE is way lower on days with high recovery.
The Whoop thread referenced above has a lot of great information.
Iāve been using Whoop this year and have found it very help. Itās not perfect but it really helps me understand fatigue and recovery better and constantly has been thinking about sleep. With my job it is really hard to keep up with sleep during the week, but Iām slowly getting better at it. The bicep strap has also worked really well for me and allows me to leave it on 24/7. While pricey, I view it as a āpremiumā service and I do believe I have gotten value from it.
In terms of sleep, here is the link to the TED podcast from Matt Walker, the author of Why We Sleep.
Joe Rogan had him on his podcast too. Here is the link:
If you wear the ring during exercise it will register activity. What it doesnāt do is try to figure out what you were doing (sport). Initially I spent time putting workouts in manually so I could recharge it then. But Iāve found putting in manual workouts isnāt worth the effort and doesnāt make much difference vs the automatic activity level detection. The calorie burn estimates are junk for every activity tracker anyway, so no reason to focus on the specific number. Now I wear the ring for workouts, and just put it on the charger omw to the shower.
It seems to key off movement/vibration, so I get a more āintenseā reading on outdoor rides than on the trainer, but they still register. It must check HR occasionally and use that as part of the activity intensity detection, you just donāt get a discrete all-day-HR log like you might with some other trackers. I think this is a battery life tradeoff, which is totally worth it given the small formfactor is the man selling point.
What might be cool is if it could link to strava and pull in workouts. I looked into it, but the oura cloud api only seems to allow read-access. You canāt write a workout onto your profile, so thatās the end of that.
Oura can actually import your cycling workouts from Strava if you link strava to the Apple Health app. Iāve done that with mine, and Oura automatically imports the calories burned and workout intensity level (based on HR iām guessing).
Iāll have to give this a try again, as I donāt recall seeing any meaningful measurement of activity, which for me mainly consists of trainer rides. If itās not measuring HR during those, then itās not going to detect much.
Iāve found the same with the Whoop. I have to manually start an activity for indoor rides.
I am a Whoop user and my Whoop has been very good about automatically detecting an elevation in HR and has been automatically logging my TrainerRoad rides.
Cross race on sunday:
I use android, for better or worse. I probably wouldnāt use apple health, anyway, though. A platform independent link directly to strava would be more accessible, imo. I was going to write something for myself to do it, but the api doesnāt seem to allow writes so Oura has to do this or it canāt happen.
Iāll wear it for a few trainer rides and see what it does. If it only tracks āmovementā, then it wonāt be useful for trainer sessions.
Happy enough with the sleep, heart rate tracking, body battery I get from my Garmin 245 (non-music). I donāt think thereās much extra you get on the higher end watches, if I recall the Rainmaker reviews when it and the 945 launched (that was one of the things a lot of fenix owners gave out about I think).
I plan to upgrade from the Bolt to the 530 to properly track bike work (TR on device, into connect from the 530) and get more out of the metrics.
Iāve had a Whoop for 3 weeks. I used a CorSense prior to that and the numbers didnāt make much sense to me based on training, sleep, meds, stress, etc. I used a VivoSmart for sleep tracking before and it was similar to the Whoop but I couldnāt seem to make much of the data. The Whoop has provided a lot more information in all these aspects. The most important thing has been the sleep tracking so far. I tend to hover around 90% efficiency which was news to me so now I spend more time in bed. Reviewing the sleep and recovery data gives me the notion that someone training hard as well as only sleeping 5-7 hours is severely limiting their potential progress.
Obviously the Whoop needs more data but itās starting to get a lot better at matching up with how I feel and how my workouts go.
what other data would you want?
