I thought I'd take a look at what was around for the M3 and give FlashLion a little credit - weird this review went unposted for 6 months.
I just updated my M3 to NarsilM and a XPL2 V6 3B - crazy amps at 5.5A, 1,460 lumens @start with only a 2.6 26 uA drain, 224 uA with the switch LED on. It has a 15 mm TA triple channel driver.