The new stuff differs mainly in that the ground wire is aluminum, full size (for the ampacity), and separate from the jacket.
My own suspicion is that this is a product that is intended to replace both AC and MC. Don't be surprised if, in a few code cycles, the sections on AC and MC get combined, and the "normal" products are no longer made.
#100279 - 11/08/0609:17 PMRe: New MC all purpose cable
From what I've been told by an AFC (Southwire competitor) engineer, AC and MC cables are treated differently when it comes to listing. AC cable has to meet pre-established specifications, and MC is subject only to performance testing.
AC & MC were under the same NEC Article (334) up until '78
#100280 - 11/09/0603:24 AMRe: New MC all purpose cable
While back a supply rep had some at the supply house - that was several months ago... From what I understand, they were still seeking approval for connectors for it to be approved as a ground path. Did they sort that out yet?
Mark Heller "Well - I oughta....." -Jackie Gleason
#100281 - 11/09/0611:55 AMRe: New MC all purpose cable
I guess I'm not a big fan of the idea because I've seen what can happen to other mechanical grounds on RMC, EMT, etc. I still always run a ground wire and bond (pigtail) to my metal boxes. Gounding is a safety issue, and I hate to think of what can happen as a result of loose or improperly installed connector. I've seen a lot of "solutions" and "time-saving" devices that have tried to circumvent a wired-in ground, but I trust none of them. IT's not worth the extra minute or two it might save. IMHO.
#100282 - 11/09/0606:44 PMRe: New MC all purpose cable