Options I have come across so far:
1. Marker Comp EPS/Piston plates -
I've never used them before. One thing I noticed though... Most other major race bindings have rollers in the toe pieces to minimize friction for release. Marker still uses the same low friction plastic that directly contacts the boot sole (i believe their newly designed 2014 Xcell bindings come with rollers but they won't be available until this coming fall). Also, I have read somewhere that the piston plates add significantly more stiffness (correct me if I'm wrong). Given all this, I'm not too excited with this option.
2. Tyrolia Freeflex Pros/RDX Plates:
I really like the Freeflex Pro bindings. I like their design and construction. I have had no problems so far. I haven't used the RDX plates before (heard they have been unchanged for many years. The same for 2014 as well). I'm just guessing the two piece plastic design won't add much stiffness. This setup is what I'm leaning towards based on what I have read/heard so far.
3. Salomon Bindings:
I like their bindings on the 2014 Stockli's that I recently demoed. They have a nice affirmative mechanical "click" action when the bindings are engaged. I just don't know what plates they offer that are worth considering.
4. Look PX race
Not a fan of the PX race bindings. Don't like their design. Had a defect once.