Several firms do road shoes designed to take 2 bolt SPD cleats, so the choice isn't so clear cut.
For me it was simple - I want to be able to wear any of my shoes on any of my bikes, so straight SPD it is.
Any recommendations? I have SPD on all my bikes and really like them. I ride in fairly heavy Shimano MTB shoes. I've been doing a lot of hill climbing recently and have started to notice the weight of the shoes, so would like lighter, racier ones but which take SPDs.