I like my Keo classics. The platform is wide enough, even for my wider-than-average feet. They don't make any noise that I've noticed. I've ridden the older Shimanos, but not the new ones. I liked them. I'm intrigued by the new design...I may try them in the future.
I know a lot of Keo riders have had trouble with rapid wear and cracking/breaking of the cleats. My gray cleats are holding up pretty well after 6 months of regular use. I'm considering getting a new set just in case, but I don't think I'll actually need them any time soon. Having said that, they'll probably break tomorrow...