My feet definitely get sweaty in GoWalks, but the shoes absorb it pretty well so they don't feel sweaty. The problem is that they start to smell pretty quickly. I do like that they're machine washable and end up washing them frequently.
I bought some last year hoping they would work well for my Disney trip. I wore them for long walks to try them out. I found that they didn't have enough support for my taste. I need a really firm sole with some cushioning for the bottoms of my feet. In the GoWalks, my feet ended up sore and I even got blisters if I walked for a long time. I ended up wearing sneakers on my trip which worked much better for me. I do like the GoWalks for wearing around town on hot days. I also like them around the house because I can slip them on and off easily.