I've got 3 different type of SPD's between my bikes, and have never had any kind of a problem adjusting to them. This isn't due to any great design on my part, more based on what I had at hand when I built the bike. I like the fact that I don't have to worry 'what shoes have I got' type issues. Both shoes have SPD cleats, all my bikes are spd pedals, I'm good to go.
Steve W
Who like to keep it simple