As you may have seen in my sig, I have an M-Audio controller-- the Axiom 61-II-- and I'm reasonably happy with it. It's the only keyboard controller I have, and I chose it because it had plenty of buttons, pads, and sliders, although so far I haven't used it as much as I'd planned to (mainly because I tend to use my Yamaha portable keyboards instead). My only complaint about it is that the keys seem a bit "noisy"-- although that doesn't have any impact on using it for recording in a DAW using MIDI and virtual instruments, and I only mention it because I have seen user reviews complaining about the noisy keys. I've seen reviews of other M-Audio keyboard controllers (not the Axiom, but models such as the Keystation) in which people said that the build quality wasn't all that great, and they were basically warning people away from M-Audio controllers-- but I haven't had that sort of reaction myself with my Axiom. So I guess I'm saying that my M-Audio controller is okay for me, although I have noticed that the keys do make a bit of noise while I'm playing it (which doesn't really bother me), and I must admit that I don't have any experience with other brands so I can't really compare them except in terms of advertised specs and features. The Code49 looks like it has plenty of controls, and while I don't have AIR Hybrid (which is included with the Code49), I do have other AIR virtual instruments, and I like their sounds.
EDIT: My advice would be to try out the M-Audio, Novation, and Akai Pro controllers in the store, if they have all three available. And when I say "try out," I realize that you might not be able to play them while they're hooked up to a computer or laptop, so I mean "playing" them silently to see how the keyboards feel to you.