Armored runs are for outside plant, or, inside plant that
doesn't have adequate cable management. I've seen armored
indoors as a "security" measure, but if you don't control
your data center, you may as well save the money since
armored cable is like locks, it keeps good people out.
It may keep slack electricians from damaging it, but
considering they are usually heavy industry, I wouldn't
rely on it for that reason alone.
As I said earlier, ribbon isn't designed for data centers,
nor is innerduct designed for ribbon.
I'd love to see some photos of people using innerduct+ribbon
cable.
YMMV.
-M<