I have a M21X, and really love it. I used it last night & this morning in pitch black woods. Each output level is very useful & very well spaced out. I'd describe it as a medium thrower, and among the very best in its class. For more throw you'd have to move up to a larger light which would not be fun to tote around on a camping trip. I go camping regularly, and bring the M21X as my throwy light. My primary camping lights are a Quark AA-X and a Zebralight H501w (both single-cell AA lights.) Not only do I like how well this XML light throws for its size, but I also like how much spill it puts out. I have a M20 with the R2 LED in it, and even though it throws well, it had very little spill compared to the new M21X.
I originally bought it as a gun light. I mounted it to my KelTec SU16c rifle, and it is awesome. Did some night shooting at our cabin....very fun.