Ok Peter,
Yeah, the 911 referance was a bit over the top... But smoke and fire travel facts are well documented. You can try it yourself. Put a 3' length of MC and NM on a brick wall, hit them both with a MAPP gas torch at the bottom, judge for yourself.
And, it's not that I hate it. But like anything else, it has a place. Single family home under 3 stories, fine! 6 story apt. building, no. A 40 story building NO WAY!
