For $800, they're easily worth the buying.
I have a 105 CTi II, which is the "fixed" version. It fits me perfectly and I love the bottom feed and eject. The only potential trouble spot is a small rubber piece in the top of the receiver. If it wears down, the shell carrier is allowed to drop too low, getting hung up between the trigger group and receiver. The shell that comes after that will get hung up- you can hit the bolt release lever and it will chamber the shell, but that's hard to get done in time when shooting skeet doubles.
I had to send mine back to Remington a few weeks back for this issue, they replaced the piece under warranty, and it runs 100% again. I need to call them and see if I can just buy a dozen or so of these pieces; it took about 1500 rounds to wear to the point it became a problem, but it is something to keep an eye on. Replacement is a piece of cake- if you have the bolt assembly out for cleaning, it's a grand total of one allen head screw to get it out. They probably could have set it up so a consumable part wasn't required there, but they didn't.
You won't find a comparable gun for $800. If I saw a new one on the shelf for that price, I'd probably pick it up just to have a spare.