I have a pair of Teva Mush flip flops, but, I don't think I would ever wear them to a park. I love them for going to the pool. I also have a couple of Teva walking sandals, one mushy and one pair not, that I do wear, but, they strap to my feet.
This year, we wore our 5 toe Vibrams almost every day for our 2 weeks at WDW. No feet problems at all other than an odd tan line around my ankles. I now have trouble thinking of wearing any other shoe than the Vibram. I even wore them in Typhoon Lagoon.