you didn't mention how many speeds you have out back, but I'm running an 8 speed 12-32 which has acceptable spacing in the rear and a compact 50-34 up front, although I could easily change the rings to something lower. the bike in question is a modernized steel roadace with a rack, panniers, and trailer hitch. loaded with the trailer, it's always in the low gear. drop the trailer and bags and hammer and it'll take to the big ring happily on the flats. It is probably more suited to a 30/46 up front, and I think that would be more than adequate for commuting/touring.

FWIW I think most bikes have gearing that is WAY too high. 34/12 is capable of over 20mph at reasonable cadence, which is more than most people can sustain for any period of time, and frankly too much if you're loaded. I'm all in favor of MUCH smaller gearing or bigger jumps up front.

my road/race bike has 11spd 105 12/28 in the rear and DA9000 52/34 up front. talk about a spread, but the spacing is still very tight. it's great!