I've got the 12s and after 400 or 500 hundred miles, no squeaks yet. To solve the squeak problem, I'd probably try a dry lube like Finish-Line Wax or DuPont Chain Saver, on both the pedal and mating cleat surfaces. Speed-play actually recommends that as part of normal maintenance.
I wonder if a good high polishing would solve the problem without the addition of a lube product that could be messy and/or attract dirt? That's what I'd try first - probably a good metal polish like made for chrome or Brasso or something similar (I've got several versions of this sort of stuff in the "polish" box in the garage), and polish any plastic contact points with rubbing compound or some version of a plastic polish. I could imagine that 2 minutes of rubbing with a fine abrasive high gloss polish would get rid of the squeaks with maybe an occasional touch up. I would think that any lube product might have to be added fairly frequently, where polishing, if it worked, would be touched up every few hundred miles or so.
Anyway, I'm interested in the topic. I just put a second road bike into service and needed a second set of road pedals. I have been riding RXS pedals for several years and have been 100% satisfied (actually one chipped (minor, still functional) when 3 years old and TimeUSA replaced it free. I was interested in trying a set of IClics or Xpresso's on the new bike, but of course was stopped by cleat incompatibility. That to me is a MAJOR error by Time - not making all of their road pedal iterations compatible.
Instead of buying two new sets of pedals, I simply bought another pair of RXS - which again, are great pedals. I just wanted to try something new, but do require to use the same cleats for both. When the RXS cleats wear out (man, these things are great for wear!), I think I'll sell both pair and buy a couple pair of Xpresso. Life's too short not to try new things!