I wear Teva flip flops the whole time when we go to WDW in the Summer or in the warmer months and have had no problems. My feet really swell in the heat and tennis shoes get snug and hot. I tried regular flip flops and they don't cut it the way the Teva's do-and trust me when I tell you I own
tons of flip flops. The Teva's have the rubber shock absorbing soles and the stretchy bands-my favorite pair cost just $16! I have even converted my husband with these and he HATES sandals.
When we go in cooler months I wear tennis shoes with really good sports socks. However, I still bring my Teva's as a back up!
If you are going to DL and are riding Soarin', just take off your flip flops and put them in the net bag with your other stuff!
Have Fun!!!