I just got new pedals for the SL Club. I previously used Shimano A520 SPD pedals because 1- I had them from my Allez which in turn left my Allez naked without pedals or I can throw a pair of flats that I have lying around on there and 2- They were compatible with the cleats I had for the my shoes and all of my other pedals.
However, as I got a new bike with all Shimano 105 or better stuff on it, it is only fitting that the pedals match. Actually, there is quite a few reasons for the upgrade and aesthetics was just a huge bonus. The wider platforms and cleats make for a much more comfortable stance on the pedal while also elongating it. The axle bearing setup is new and improved and the weight difference is negligible in either direction claimed/actual weights.
It doesn't seem as though my current shoes will take all 3 bolts for the cleats due to them being beaten for a good 2k miles. I am sure new cycling shoes are in my very near future to accommodate this.
The clip-in system is very similar feel to my old one with a loud enough click to know that you're in, but it is much smoother both on the clip in and release to/from the pedals. I will report back in a couple of weeks with some real updates, but here is the bike with the new pedals installed.