As someone who has leveled both human and iksar to 60 and raided both extensively. I will have to say hands down Iksars are much better for all types of game play.
The regeneration alone is enough to make me never want to roll my human monk again.
I played a 60 human monk on blue for 4 years, then went to red before velour and played iksar monk there, got 60 velious dropped and he was awesome. After red started to totally die I came back to blue and playing a human I could see / feel how much the regeneration made a difference. The numbers over time are insanely huge. I rolled an iksar monk on blue and never looked back.
Yes youll level a human monk faster but if you play the game correctly you'll be level 60 for much longer then the time it takes to get an iksar monk to 60.
TL
[You must be logged in to view images. Log in or Register.]R iksar > human coming from the weirdo that leveled 4 monks on p99. 2 humans and 2 iksars