I like mine, came with the jeep, though I havn't put near to 500lbs on it yet. Works great for random stuff, tools, supplies, whatever. Glad I have it. Would be kind of a pain without it, as I'm used to driving a truck with a bed around.
There are hinges in the back, so you can fold it down to remove the hardtop - or the whole thing can be removed with 4 bolts. Also makes a handy place to attach a CB antenna, offroad flags, and I plan on using it as a lightbar when I get the cash. Looks cool as well, though it probably costs me a couple mpg's.