Originally Posted by Proximo
A 50-11 is a larger gear than a 53-12 so a compact double will give you plenty of oomph if you don't mind tinkering with the rear cassette.
Personally, I have a Shimano R700 50/34 compact double on my Merlin with a 10sp 12-27 cassette and love it. I have an Ultegra 6600 triple with 10sp 12-27 on the Sequoia and much prefer the compact double. I do a lot less shifting with the compact since each ring let's me comfortably use 8 of the cogs. In hilly country, I stay on the small chainring and on the flats or long descents, its the large ring.
And a 53-11 is a larger gear than 50-11. Changing the cassette is MUCH cheaper than changing a crankset AND cassette.
If your triple isn't shifting as well as a double, compact or full-sized, it's adjusted wrong.