i'm very interested in a road setup. i'm looking at the spd-sl and a pair of either sidis or shimanos or specialized, but i don't know that it will be worth it on rides shorter than 30 miles or with more than three stops.
i like my used m520s just fine and maybe i just need to get new shoes and pedals to keep from unclipping as much and keep my shoes performing well. my race shoes are really ****ty adidas that have all but broken.
the big problem with SPD-SL is that my rondels would be useless on whatever bike they're on, and the big problem with new shoes and pedals is that i could just as well go SPD-SL.
road clips are harder to clip in and out of but offer more support and better power transfer, from what i gather. for 95% of my miles, that's not going to outweigh the decrease in convenience.
so i'm pretty conflicted, because new pedals and or shoes is a ton of money to not have it be way better that 5% of the time.
i think i'll probably end up just saving up for some shoes before i do any races, and going with my current spds.