I use Velosambas daily, and I think I've previously recommended them in here? The only caveat I'd add is that while they worked perfectly for me when I was using eggbeaters, I recently switched to SPDs which have thicker cleats; between that switch and also repositioning my cleats for a more careful fit, they now contact the floor when I walk normally in my shoes, to the point where I feel the need to wear SPD cleat covers over them at work.

It's not great, but I still prefer using them this way to carrying an extra pair of shoes to work in the mornings. But maybe look for shoes with better cleat clearance if you're going to use SPD.