I use both on separate bikes. Ultegra is very smooth and the shifting is effortless. But for a sprinter, it's almost too effortless; there's less feedback and when you want to lay down the watts at the moment your bike is in gear, feedback is important. The ultegra shifter has a lot of leverage on the derailleur (the whole 2:1 thing) so it takes very little force to shift, but on the downside, it requires some fine adjustment and sometimes misses shifts, particularly in the downshift direction.

SRAM is "clunkier" by design. The shifter has less leverage on the derailleur so it requires more force to shift; on the other hand, it is very precise with lots of feedback. When it shifts, you know it, and there is no need to fanangle it into gear.

Basically, I like to climb and do long rides on the bike with the Shimano shifters, and I like to sprint in crits and circuit races on the bike with the SRAM shifters. Obviously I can do either on either, but I favor one over the other depending on the situation.

As for cranksets, nothing beats Shimano. Not the lightest, but the stiffest and easiest to set up by far. Also, as far as I am concerned, Shimano always has had and always will have the lead in cassette technology. They were the first out with the ramped teeth and IMO, still ahead of both Campy and SRAM in cassette design. Even on my SRAM bike, I use a Shimano crankset and cassette.