Awesome piece of gear!
I've been using an ATC since I started climbing, and just got a Gri Gri. I LOVE it. It's awesome for belaying, feeds rope super smoothly, and lowers well. It's great for top rope, because you can let your partner hang while they work out a move, which makes belaying a lot more comfortable. It catches really well too for lead falls! I do have big hands, which did take a bit of getting used to, but now belaying with it is much easier. I did notice, that the Gri Gri 2 isn't exactly the biggest fan of fat, fuzzy gym ropes. It can be a bugger to belay with then, because it doesn't feed as smoothly as I'd like it to. Other than that, I absolutely love it!