I bought my first pair three months ago, and as I always do with workout/running shoes, buy a half-size larger. They fit quite well considering I have a very narrow foot, and I'm wild about the stability they offer. For me, they don't offer much arch support, so for some of the workouts where you're doing a lot of jumping on and off the step with both feet at the same time (the straddle down, up down; up down up type stuff), my archs really cramp up. I'm sure it's more a matter of my foot makeup than the shoe, but just thought I would throw that out there.
Beth