Whether I spend "a lot of time" at those speeds or not, when I want my 53x11, I generally want it bad. For example, downwind sprints at Spokane County Raceway can get into the 40mph+ range, and I'm not one of those gifted 120rpm-out-of-the-saddle guys. It would be silly to go to that course with an inadequate high gear on the grounds that "well, I'll only need the 53x11 for the last 200 meters, so why bother having a 53x11?"

bhaubold, another factor to evaluate is the jump between the rings. The jump from a 34 to a 50 is about a 15% larger drop in RPM than the jump from a 39 to a 53. In practical terms, it means there's usually one more rear shift required to compensate for a front shift, and less overlap in the speed range of the two chainrings. That can be viewed as good or bad, depending how you ride and what you like better.

I do have one of each myself... the rain/commuting bike currently has compact. When I change it from 9sp to 10sp, it's going back to full-size, though... personal preference, I guess.

Oh, and to address the actual question: rather than changing rings on the compact, I'd recommend getting a non-compact crank if you want full-sized chainrings, for flex reasons.