I seem to recall a discussion somewhere about the issues surrounding "free flexing" binding systems. There are different ideas about how this should happen from the manufacturers, but there was a point that each manufacturer ended up doing it a slightly different way due to patents they had.
In the case of the Railflex both the toe and the heel slide and the center is fixed to the ski. In the other Tyrolias only the heel slides and the toe is fixed (I believe that this is the method that many others use also, except Marker). Marker's motion system has a fixed heel and a sliding toe (if I remember correctly). According to the article (or the discussion - can't remember which) the general consensus is that the best method to achieve "binding freedom" is to either allow both the toe and heel to slide or just the heel. There were some fairly negative comments about Marker allowing the toe to slide forward while the ski is flexing. Unfortunately I can't remember the technical issues, but I remember the argument being fairly sound.
I had every intention of mounting some Railflex systems on my skis, but ended up having to return them since the Railflex base was much longer than I had anticipated and proved to be incompatible with the risers and plates I had on my skis. I'm still planning on using the Railflex if I end up picking up some Stockli Snakes for the new season.
After my discoveries regarding binding coupling stiffness (there's a whole thread on that from a few weeks ago - most of it is worth reading) I don't think I'll be purchasing any more Marker bindings in the future. So my vote would be for the Tyrolias.