I find UK to be very easy and damn quick since the only boss ability you have to wait for is the last one when he dies and comes back. On the last boss you in theory move your toons behind a pillar before he comes back to live, a simple move left before and a move right after and it's sorted. I've only 5 boxed it on normal so far since I'm 3 levels off 80. Only 3 bosses tho.