I have been using toe clips on my old bike, but now that I got a new race bike I am thinking about trying something new, such as the SPD. Because I like the idea of being able to walk a little bit when I get of the bike. Specifically, I am looking for the Shimano PD-A600. But I saw most people here use the Look/Speedplay/SPD-SL pedals for their race bikes. For racing and training purposes, would SPD work fine? Would there be a disadvantage for using the SPD for racing?