When I bought my bike back in 2005, I spec'ed out a full Centaur double drivetrain with 53/39 and 12-25. I was working in Taiwan in a relatively flat area and this worked very well. Later on a spent time in a city that was much surrounded by fairly hilly areas. I went on a few rides with a local club and there were some short steep switchbacks that scared the crap out of me because my cadence would get very slow. Slow cadence and slow speed while being clipped in is not a good situation. My solution was going to a triple as this was well before Campagnolo introduced that 30-tooth 10-sp cassette. The place where I bought my bike, GVH Bikes in Oregon, was selling off some previous year's inventory and I bought a Centaur triple crank and long cage rear derailleur and a Chorus front derailleur for a triple. Now I had a 53/42/30 with the same 12-25. That worked out well with the 30>25 for hills and the 53>12 for the flats. When I upgraded to 11-sp, the Athena triple didn't come out until later. I would have preferred that to the compact.

Miche is an alternate source for Campagnolo-compatible cassettes. They have combinations that Campagnolo doesn't have...