Power Grips are great. I've commuted on them for years and they're perfect for that task. You can wear any shoes you want and they're easy to get in and out of. Just twist your foot a little and that's it. Installation takes a little longer, but they stay where you want them and I haven't been able to break one of the straps yet.

I could be wrong, but I do feel like they make a difference over plain old platform pedals, especially on hills.