Pearl iZUMi vs SIDI bicycle shoes?

I'm a diehard SIDI Geniuswearer, but you can't buy shoes based on the brand. Some shoes by the same maker will fit differently. Both companies make great shopes and you need to try them on to see which one fits you best. I can't say there are better companies because that's an arbitrary statement. There are shoes that are better fitting but the shoe for you is the one that fits you well and looks good to you. Just remember that your feet are your feet. What feels right to some else might not feel right to you. Try them all on. By the way, Shimano, Diadora, Vittoria, Specialized, NIKE and many others sell cycling shoes so your options are virtually limitless.