I am a long-time user of the Fritschi Freeride Pro, and for many years I have been dissatisfied with the poor energy transfer, height of the binding, pre-releasing- all of the common complaints. I continue to ski with the Fritschi because I’ve had a number of ACL replacements and cannot consider an alternative AT setup due to concerns with binding safety. In-bounds I ski with the Look Pivot setup, and am so satisfied with this binding technology I have longed for a system that would allow me to use a pivot heel when touring. Two questions on the MFD setup:
1)In tour mode, I am weary that the location of the pivot point being in front of the binding would make touring much more difficult. My thoughts are it would be much more difficult to 'lift' the binding when stepping forward. Thoughts?
2)Concerning the flex of the ski mounted with the plate, I am aware the locking piece ‘floats’ to allow for a natural flex of the ski, but does the overall length of the plate have any effect on flex?

To answer this: 1. The pivot point is perfect. I just used them for the first time these past 3 days and I did not notice a difference compared to the Fritschi setup I used last year. 2. I noticed no difference. I have them mounted on a somewhat playful powder ski (ON3P Caylor), and I could not tell any difference between them and any other skis I have used.

I bought a pair after doing similar research to the questions you ask. Turns out my bindings didn't fit after all, but I got a close look at these AT-ATs (hehe, pun intended). 1. The pivot point wouldn't be as wearisome as the extra weight required to lift. Actually the pivot point is pretty efficient because it is above the toe piece instead of directly on the toe piece, allowing easier rotation initiation of the whole plate. The worst would be the weight of this compared to other heel lifting setups, but I figured I'd ride max 50/50 on resorts and in the backcountry, so it would be worth it. 2. The blister review addresses the ski flex issue on page 2-definitely read the section entitled "large deflections and shear forces?" the reviewer did a computational assessment of a ski. Specifically the floating heal block easily counters the deflection issues and shear forces on the ski and not the natural flex (though it has to help). I personally think the natural flex of the ski has to lose something with such a long plate because the reaction points from the mounted plate sit further out, resisting the flex of the ski more than a regular mount. However, I'm not a racer, so I didn't think I'd notice too much anyway. Hope this helps