i have a bike with 700c, a bike that had 27's and went to 700's (fixed), and one that is still running 27's. i use the bike with 27's for touring (a 1 and 1/4 tire is ~32mm). plenty of good tires are available in 27"- i love my palsea tourguards (panaracer). used them about 2k miles and very few flats.

the main reason im looking to switch to 700's is so i can run some 28's with fenders. im hoping they can be squeezed in there with the reduction of tire radius (its way too tight right now). id stick with the 27's and try some good tires.