I'll give the 28c a try. jm01 -- I've already got the LBS set to swap out the drive train to a touring setup similar to the 7.5fx. Coming from the mtb side, I'm not a speed demon but I want to be able to tackle the "hills" of western Colorado without worrying about getting to the top.
Like late said -- reliability and comfort are more important than speed. I'm assuming I'll have more flats with 28c or 32c than I'm dealing with on my fat mtb tires.