Well mine were probably more of a necessity because I was getting foot pain too no matter how many different things I tried. One spin instructor had been suggesting them to me, then I started taking another class with my yoga instructor and she started to suggest the same. Well, and many people in the class already using them and raving.
Someday I am hoping to get comfy enough to change the pedals on my regular bike to use them too.
The improvement in class was way beyond no more foot soreness. I'm using more of my leg muscles and I feel comfortable to work much harder. I have cleats on them so my shoe is attached the pedal, it's easier to do a full circular motion when pedaling compared to when my other shoes were just in the toe cages. I always felt like my feet were a little unsteady when I was in a standing position so I didn't go as fast as I would have liked - I don't even worry about my feet now. Now that I'm used to them, I can't imagine not having them.
I got Diadora Escape shoes, I think they were called. I went into a cycling shop (Performance Bicycle if they have any of those near you, I know it's a chain) and just tried on every pair of indoor or MTB shoe since most of them mentioned 'spin' or 'indoor cycling' on the signs above them and tried to pick a balance of cost and comfort. I was pretty clueless but they were very helpful. The cleats aren't included so I got those too. They were nice enough to show me how to put the cleats on the shoe, and they put them on for me.