I just put one on my '93. It's a Bestop Halftop. It leaks pretty bad in heavy rain. Mainly around the roll bar collars, and the long stitched seam where the cab back and deck cover meet drips like crazy. Also the door seals are being pretty difficult to line up right, and it's leaking around there. Scotchgard helped a little with the seam leaks, and I'm going to try adding some nylon straps around the collars.
So maybe not the best for keeping it dry, but I just keep a cab cover in the back to throw on if we get a big storm. And keep my floor plugs open. Because I really like the top!