I have the M3C4 3xXP-G and it is a superb light. Floody? Yes, but so impressively powerful that it throws further than you might expect. To solve the flat-top battery problem I just transferred an M2 battery caddy from one of my M2 lights to the M3 and it worked perfectly. The usually intelligent Eagletac designers really dropped the ball with these new, highly impractical battery caddys. Hopefully Eagletac will quickly correct this design error by sending out the old caddys free to every M3 purchaser.
I doubt that Eagletac's original M2 thrower, the M2XC4 3x XR-E R2 will be surpassed until an LED of identical or smaller area with superior surface brightness is developed. The new smaller-diameter XP-E's (XR-E's?) are evidently not significantly brighter than current models, though they might produce a tighter beam. (Please correct me if this is not accurate).
So if the M2XC4's (6000K white LEDs for maximum throw) are still available and cheaper than the M3 equivalent they would be a better buy. However, your personal needs might prefer the M3 version's more flexible UI and improved handle. (I don't know if they have managed to improve the new version's efficency).
The M3 models have an improved handle/battery container design. One of its several practical features is a lock-out that occurs with only a 180 degree turn, rather than having to unscrew the handle almost until detachment. This makes carrying to avoid parasitic drain but quickly ready for action much more convenient.
Brightnorm
I wouldn't think about the M3, since it seems to have a massive lack in output. 409 OTF Lumens in Turbo is ridiculous.
