Been doing some research.

[LUTNIT]

It would add a little more need for higher torque, but as far as I know it doesn't make that much of a difference. The Guarder blowback kit for AK's and the STAR blowback kit for L85's don't noticeably effect battery life from what I have read.

On the note of power, I am really glad to see TM finally going with NiMh over NiCd.

*Edit*
Just found some more pics. Looks like TM has removed the battery connector totally as well as all wires. This makes for a nice clean no-hassle battery solution but at the same time means you can't use normal batteries without some custom workings. Looks like no room in there for an adapter so you would have to rig batteries with the new TM connector. Very clean but like the new M4 mags, you can't use your old bits with the SOPMOD.