I have a smittybilt top on my TJ. I bought it new about 2-3 years ago. For the price, it's a pretty good top.
I like the tinted windows in the back, they are pitch black. You really can't see through them from the outside, it looks really nice. It is 100% waterproof, never had a leak, even in some torrential downpours.
However, despite there being no leaks, the top does let a bit of moisture through when it rains. If you place your hand of the roof of the top from the inside it is slightly damp. In other words, it does let a lot of humidity in. Not sure if that normal with all tops though.
Also, the stitching has come out in 2-3 ares. The velcro near where one of the back windows attaches has ripped out a bit. You just have to be careful and go slow when folding the top up or down. Never force anything....that's where I went wrong.
All in all it's a good top for the price. I'm happy with my purchase, never once regretted it. That said, if I were to buy another top soon, I would seriously consider the quadratec soft top. A bit more expensive but I've heard great things about them. Supposedly they are exactly the same as OEM tops, but don't quote me on that.