If the tree fits your horse, then they are great saddles. I still have my first saddle, a Wintec 500 that is over 9 years old and is still going strong. I've had it on probably 5 different horses, but mainly my fat, fat, fat Arab.
I've found the older 500's have a flatter tree, while the newer ones (I also have one that is only two or three years old) tend to be more banana shaped. The tree can't be changed, only the gullet, so as long as the tree fits your horses back shape, then they work well.