I wore open-toed, sling-back Sketchers to a local amusement park this weekend. Not only did I get blisters from them, but my own DD6 stepped on my toe twice and it hurt! I wore them as an experiment because so many posters say that they would only wear sandals to WDW. I have always worn running shoes (lightweight, breathable) with socks to parks, so I thought I'd give the sandal thing a whirl to see if it was comfortable. I have to say, I never get blisters with sneakers/socks and my feet are protected from strollers and other hazards on our miles of travel on WDW park days.
Please note, I didn't get blisters from these shoes before. I would think there are others out there who wear sneakers, but most posters discuss wearing Tevas and the like with no problems.