The M6 LED is the same host body (though going through some changes) as the incan version but it has a 1 watt lamp assembly instead of the incan and comes with a clickie (some red, some black). The M8 LED and SabreLite are both 3C LED light that uses Pelican's "Recoil Technology" which has the 1 watt LED mounted on an aluminum bridge and faces into the reflector so that 100% of the light is gathered, focused and reflected at the target. The M8 uses a clickie on the body and the SabreLite uses a twist on/off, but is submersible while the M8 LED is only "water resistant."
Oh, and the M6 and M8 put out a nice tight beam for great throw, but the M6 has side spill while the M8 has very little to none at all. The SabreLite hasn't come out yet.