The SPC (Scalable Plate Carrier) isn't an MTV replacement. It's part of that whole, "Let the Battalion CO Decide" approach to body armor. The MTV is an abortion, though. We fielded a couple different versions in 2008, and although the issued one has sewn-in soft armor, one of the other models was more to my liking. I swear that I have NO idea what happened to it, nor did I use it on a subsequent deployment, with non-issue (read: BETTER) plates.
But I digress.
LINE and da Fu are basically the same in my book: Something to teach just enough of, so that Marines go out and get beat down when they try to use it.
ETA: I meant that we fielded a couple different plate carrier models, not MTVs. And yes, I do find it ironic that the acronym for the annoying, uncomfortable, chaffing plate carrier is 'SPC'.