1st and foremost, these are jazz shoes so you need to buy these 1 whole size up unless you like your shoes really narrow and tight against the skin. (Uncomfortably so I mean.) Dance shoes are not work shoes so they should fit slightly more snug. As others have mentioned the bottom is slick like plastic which would be dangerous on a slick floor such as at a gym. As someone who will be using them on slick, hard floors, I personally wish they had a tad bit more traction, but its nothing a little sandpaper or razor won't fix. Otherwise, they are very comfortable, and they also breathe well. They are really light which is great when you're dancing. Def. a great buy, and they are significantly more comfortable than my previous pair from a different brand.

***Update*** After putting them to the test at a high impact Zumba class they were still very comfortable at the end of the day and were easy to move in. I still maintain it was a must to order a full size up, and a little extra traction should be added if using a particularly slick floor as there were times I was kind of sliding around.