This kinda technology has kinda been in the shadows (since ~2009), and to be honest, I've only heard of it a year ago or so.
So the idea behind M-Disc, is that actual holes are burned through the metallic layer, instead of turning them a darker shade as it is with regular CD-Rs.
Supposedly, this simplified construction (quite similar to the old red-book CDs), is supposed to have a greater longevity, and be read-compatible with any existing players. The biggest drawback, seems to the fact that you need a special recorder, and the fact that they're pretty expensive.
Has anyone ever tried them? Are they really compatible with existing players (drives)? I might be in a situation where I might need an optical drive, soon. I thought about getting one that can record on M-Discs, and perhaps use those instead of regular CD-Rs from now on. Sure, they're more expensive, but I record on CD-Rs so rarely, that I might as well get the newer technology thingymagic.