I am 5'11". Will I have enough room to...
I am 5'11". Will I have enough room to sleep without head or feet hitting a wall?
Yes, it should work out great. The tent is 82in long and 5'11" totals 71 so you should have enough extra space to prevent that from happening.
If you're using a thick sleeping pad I wouldn't count on it. I'm 5'8" and with my 2.5" pad, I'm almost touching the ends of the tent, literally with about an inch to spare. This is not a large tent.
I'm 5'10", and I can just fit with my old model HiLight with a 2.5" Exped pad. The new, green model is slightly larger, so you'll probably fit, but just. I'd pitch it inside to make sure it'll work before getting it dirty.