Right now I have a 34-50 crank, and 11-28 cassette.
Have no problems with the low gears on climbing, but there are sometimes that when riding with a group on a gently descents, at~30 mph, I don't have the high enough gear, and should spin at a very high cadence.
So the sram 12 drivetrain, with 10-33 cassette, and 35-48 crank, actually covers both 34-50 and 39-53 traditional crancksets. And I like this idea very much.