I did it for a long time! About 2 years and 500 competitive miles. For what they are, Wintecs are great saddles.
It worked pretty well for 15-20 miles a day at novice level. But after I moved up to 50s, my horse started coming up sore in the loins. I figured that my Wintec 2000 just wasn't doing a good enough job of distributing pressure. Or maybe as my horse was getting fitter and older, she was changing shape and the saddle no longer fit.
Not having to deal with leather was awesome though, I'll tell ya.
If you're just needing a versatile starter saddle, a Wintec is a good choice.
They are hard as an effing rock compared to a "real" endurance saddle though. I would recommend a sheep skin.