In reply to johnboybuchan:
I have got SPD MTB shoes for my mountain bike - big enough to wear with very thick socks, because MTB is a winter affair for me.
I have touring SPD shoes for my commuter - nicely walkable, comfy but a bit bendy and a distinct point load when pedalling hard.
SPD-SL road shoes for the road bike - light, close fitting, far better for doing that hard pedalling thing I hear people talking about. Comedy moments galore on slippery café floors. No real difference in unclipping between SPD and SPD-SL. There's something about road shoes though - after a couple of winters of water and grime they smell of nettles and wee, and the smell will not go away despite bunging them in the washing machine. Just bought a new pair: Mavic to replace Sidi for me, based on the comfy touring shoe experience.
Post edited at 17:20