I put 28cs on my fixie, which has a very steep geometry (I think the head tube is at 74 degrees) and immediately noticed a gentler ride than the narrower 23c tires. But the steep angle makes for a fairly harsh ride on that bike; on the bikes I have with a more relaxed geometry I notice less difference in ride between tire sizes. One of the advantages of a slightly wider tire is fewer flats (or at least that's what folks tell me; I'll go a year without a flat and have three in a week, go figure). Specialized armadillos are noted for their flat protection, BTW, but I have yet to ride on one.