I have one, so does a good friend of mine, I have a 2000 AP she has a CC. We are both very satisfied with the saddles. The only bad things I can say are the wider gullets (with the Easy Change system) are hard to put in sometimes, and the synthetic stirrup leathers get really really stiff in cold weather.
Out of all the synthetics out there I personally would go for a wintec, they seem to fit the best and I haven't heard of many issues to do with horses backs. But I have seen a loooooot of back issues caused by the inter-changeable gullet systems. Wintec or otherwise. They simply do not hold up properly and tend to create a hard hollow back.
I ride in a Wintec Isabel and absolutely love it. It fits my very hard to fit Paint and is so comfortable. I do alot of trailriding in it because it's so comfortable for both of us and has a nice secure feeling. I also school him in it too.
I love wintecs! I have a wintec western and wintec a/p 500. I feel like the wintec western isn't nearly as comfortable as it could be, but I've certainly ridden worse. I'm pretty happy with it, I just wish that they would improve upon it a little bit, by making it more comfortable and able to better fit more horses. But with that said, I feel like it is a good choice for me. It's affordable, easy to care for, and very durable. And every time you wash it it looks brand new!
I absolutely love my a/p saddle. It's very comfortable and has the easy-change gullet system so it fits almost any horse. I also love the look of it. I just can't say enough about this saddle, I love it so much =D
Maybe I am a little bit biased in that I am vegan and only use synthetics, but I think Wintecs are awesome! I recommend them to anyone who's looking for a durable, affordable saddle.