I'm in the same boat, mostly. Keyboard and mouse for any 4 or 8 mans. Controller for everything outside of that. I'd like to get as good at controller as I am at keyboard/mouse, but I just started using controller for this game about a month ago, so it's going to take awhile to catch up since I've been playing MMO's since EverQuest.

Controller is so good on the wrists.. especially my left wrist. I guess I'm getting old but my left wrist gets uncomfortable after a few instances of mashing buttons. I am grateful that the GCD is longer than it is in WoW. It allows a lot more rest time. So if I can get good at controller, I'd like to just switch to that 100% of the time.