XT would shift nicely - of the long-cage options out there, it's probably among the best. I have a friend whose Trek Madone has XTR for a rear der (with a 11-30 ten-speed cassette) and a compact double (34-50) in the front - a setup he bought for last year's Death Ride. He says it shifts as well as his Dura Ace setup ever did (he still has the DA brifters and front der).