I have tested the battery but not the grips (they sent them for the test but I did not need them). The light was not available at the time.
Strong points:
Shoot all day and then have power to spare.
Integrate with light.
Weak Points:
Under camera mounting. By the time you add Elipz and possibly Firestore or CinePorter (when available), camera ergonomics are thrown off.
No option to offer longer cable to mount battery elsewhere. I suggested this to AB but they were not terribly interested. I modified (or rather Danny Natovich) modified the cable to be able to mount the Elipz on DVMultiRig (he just made a splice and lengthened the cable).
Propriertary connection for light means you can only use their light... no standard A-B tap.
My bottom line-- a very good extended life battery with some quirks.
Absolutely love the MultiRig. It is tremendously versatile, stable and adapts to just about any shooting situation you can imagine. I am very pleased with it and won't do any run and gun shooting without it.