I think clip-in pedals ("clipless" seems a bit of a misnomer) are overkill for most commuting. They're fairly easy to get used to, especially the SPDs, but they don't improve performance on level ground at all, and they're a pain in the a** in traffic. On hills, they do make a noticeable difference, maybe a 5-10% improvement in performance, but if you're just commuting, that difference isn't worth the hassle of having to wear dedicated shoes and having to endlessly clip in and out at intersections. I prefer studded platform pedals in nearly all urban situations; if you retain your platform skills, it's much more convenient, and your actual performance, if you care about such things, is very nearly what it would be with clip-in pedals. I used to use SPDs for touring, but now I don't think I'd use clip-ins for any reason, ever. They're simply not necessary if you're not mountain biking or racing.