I've never ridden in Wintec Endurance Pro, but I ride in a Wintec Dressage Pro which has a similar depth of seat and the same all-over synthetic suede-like material. IMHO, the saddle is very comfy, with enough grip to provide your muscles some relief over long rides and through feisty pony fits. ;)
As for durability and washing, anyone will tell you how nice it is to be able to brush or hose off your saddle when you're done! Mine still looks brand new.
I also like the adjustability of the saddle-- between the changeable gullets and easy riser system, I can fit my horse (a big-boned 15hh arabian) well and change the fit (within reason) as his musculature changes. The easy change system won't make a Wintec fit every horse, but it does broaden the number of horses you can fit.
Finally, as for the CAIR pannels (air/foam as opposed to typically flocking)... I have an AP with CAIR and my dressage saddle has regular flocking. My horse vastly and obviously prefers the CAIR pannels over the flocked pannels, but my dressage saddle is flocked for the simple fact of durability (many question how CAIR holds up over time) and the ability to re-flock it if it absolutely won't fit. That being said, my AP with CAIR is a used Wintec 2000 (the older model) and the CAIR pannels are fully intact and functional.
I hope this helps! :)