The reasons I want to use speedplay pedals are:
1) I think that I will be more comfortable with the free float on speedplay as compared to float with friction on SPD-R
2) Stack height seems to be lowest on speedplay with a four hole pattern. It looks like I will have to use a Time compatible shoe in order to use the 4 hole pattern. With a 3 hole pattern, the SPD-R is only .5 millimeter taller
3) maintenance looks very easy on speedplay
4) It looks like a good system for the road and I want to be able to use the same shoes for road and track
If the pedal axles do become gouged to the point of detriment to safety, then maintenance won't be an issue. I'll have to replace the pedals.
I currently use Shimano PD-M505 on my Bianchi Pista, setup as a track bike (no brake). I have the spring tension cranked all the way to the maximum. I don't mind the effort required to get into the pedal but getting out of the pedal isn't always easy. I'm currently using touring shoes. It should be easier to torque the shoe out of the pedal with a stiff soled racing shoe. I do all of my riding on the road right now but next year I will be in NYC at Kissena and T- Town so I am planning my equipment at this time.