Depends on how you play, and what epic pool. I went with cardiac on mine, but I have a lot of weakly slotted for end redux AoE, with fire mastery, and tough/weave/manuvers, plus hasten. If you don't have the extra toggles, you can probably go another way without issue, esp if you slot consume. If you have conserve power/pp, you can easily go with another.
I know Cardiac is a safe bet. Got it for other alts and love it.
I dont have hasten in my build, and have around 50% global recharge thanks to set bonus...
Should I get Spiritual? Recharge, healing, and even stun duration for the martial arts attack sounds pretty good to me.
Musculature maybe? I dont think so...
Nerve not even an option, lol
What do you guys think?