The newest model of most wintecs come with suede. I'm guessing that Wintec thought that the equisuede was too slippery for eventers or jumpers so they decided to "help" us stay in the saddle.
I used to ride in a wintec 500 without suede and I loved it! I felt like my knees made impressions in the knee patches and therefore my legs had a comfy cove! But when I was riding my super bouncy mare it was a little slippery.
Now I own a wintec 500 with suede knee patches. I really feel no difference in the saddles at all besides the patches. It rides the same except for one minor detail; the temperature. The suede patches haven foamy material under them so your legs conform to the saddle (much like the old model) but the foam and suede combo traps heat under your legs so if you are riding in shorts... Be prepared to be toasty!
But overall, they feel totally the same in my opinion besides the heat. The knee part doesn't even feel different, it just looks different.