@Halley…When I moved from a 66mm depth Reynold to the ENVE 7.8 SES the difference in control at speed during cross winds was nothing short of amazing. The internal width was a further revelation. The textured brake track a third. Control speed and braking all superior. In fact the 7.8’s outperformed my old (now sold) ENVE classic 45’s in control and obviously blew them away in speed and braking.
Further, I own a set of Knight 35’s. I’d choose those in an ITT before the Reynolds or the ENVE classic 45 which are obviously both deeper but both more of a narrow-v shape. They are simply faster. I attribute this to the wider internal and external width of the rim and how that affects tire shape/performance.
Last anecdote…I briefly owned a set of ZIPP 808 Firecrest set just prior to the ENVE 7.8. Their hubs while arguably “fast” I find a PITA. The 7.8’s are laced to DT Swiss 240’s which are bombproof, easy to work on and roll nearly as well as anything IMO/E.
Jim Manton said some interesting points in a recent “Faster Podcast by Flo” about shape and how it contributes more to speed and control than depth of rim.