I got a good fit from Smiley and went with the Frogs -- they're my first clipless, so I've never tried anything else -- so maybe it's all about what you're used to. Smiley definitely has his opinions, but ultimately it's your bike and you should have it built up so that you are comfortable (and safe!) with the components.

Frogs are nice for their recessed cleats and degree of float, if you are concerned about that. But if you are happy with your SPDs, I don't see why you should make a change.