I read the reviews saying that these thing hurt, and they sure do. In fact, they were like spikes in my feet for the first three days. Then, once i broke them in they feel amazing. It's one of those things, if they hurt, you probably need them. The reason I was okay purchasing was that I've seen this "foot massage spike thingy" technology before so I knew there was a method to the madness. They feel great on my feet now.
I have sweaty feet when I go to a tropical place. This is the perfect sandals for me. Even if my feet gets wet, it won't slide out and it won't make those muddy thing caused by the sweat plus dust. I also like the spikes on the foot pad as I think it is healthier this way.
I was reluctant at first to order these based on the reviews posted, but I'm very glad I bought them. My feet are pretty sensitive and the "spikes" don't hurt at all, they feel amazing -- ESPECIALLY with no socks! I've been wearing these around all day and don't plan on taking them off until I go to bed :) I usually wear a 9.5, ordered a 9, and they're a tiny bit long, so you'll probably want to order a half size to a size down depending on how wide your feet are. The strap is adjustable, though.
I hate these sliders because of the unbearable discomfort of the plastic "spikes" I have no idea how anyone would like anything but a smooth surface under his feet. I couldn't wear these sliders more than an hour! My feet sere sore for the rest of the day!