i changed from a triple to compact recently and its been better than I expected. the shifting is actually improved and my gearing is pretty much the same, I haven't hit a climb yet that the compact can't accommodate that my triple could.

Add the weight savings of the compact cranks and that you should be able to use your double fd rather than switch to a triple fd, and that you don't have to make sure your left brifter can throw for a triple and it makes sense (to me) to go to a comact rather than a triple. nothing wrong with a triple but the benefits just aren't there in going from a double to a triple over compact unless maybe your climbing the alps without the legs for it.