As with anything it has to be "joe" proof, or as I like to say "bravo" proof.
It needs to be able to stay on someones gear indeffinately, without having to worry that it will break. Few moving pieces, and as close to indestructable as you can find. Nothing worse than being out in the field, and finding out (usually at the worst possible time) that something doesn't work or is broken, esp with a piece of life saving gear.
As for a field study, I know a lot of units have fielded and are currently using the CAT, and the SOFTT, in the GWOT, haven't heard about the MAT. I'm sure there have been studies done, on how they are doing.