I've been using the Naga for about a year now and can't imagine going without it. First week or so is a real pain though, needed the little nub sticker they provide just to start building the muscle memory for button placement. They wear off after a while, but by then you don't need them.
If you get a naga don't get the epic edition. QC on razer wireless stuff is pretty poor, honestly I think their QC as a whole has gone down over the years (not counting the Nostromo because it is actually a belkin product rebranded/tweaked). The epic Naga has lots of issues when used wirelessly with random disconnects and losing pairing, etc. which Razer states they fixed in a firmware but the issue still exists.
You can still use the naga epic as a wired mouse but why pay $130 for the wireless version if you're going to use the wire anyway? It (the epic) also comes with 2 additional side 'molds' for different grips but they are pretty poor and you'll end up using the default one anyway. Save yourself the $70 and just go with the regular naga.
If you want a wireless mouse go with the G700 it's superior in every way. Much better build quality, plenty of
useable buttons (you will not use the 10,11,12 row of the naga), and uses AA rechargables rather than the proprietary razer battery. So you can buy some rechargeable AA's and a charger ($20 or so) and just swap batteries if you run out without having to go wired. I tend to like the setpoint software a bit better than razer's as well.
The regular naga and G700 are very fine mice, the epic has issues.