yes it is! i'm using LR attys...which will drain any battery faster than a standard atty/carto will, but the 2900s still perform strong long after my IMRs quit. the IMR is great for smaller sizes like the 16340 and 14500 where the same sized li-ion (cobalt) battery couldn't handle the amp draw and would drain it even faster, but at 17670, 18500 and particularly this new 18650, you get long life and drain rates well above the demands of any LR atty/carto. i get roughly the same perfomance from an AW IMR18650 as i do from the conventional li-ion AW17670, which is great pretty much all day performance, but given the size of the battery it could be even better. the way i see it, if you are going to use a bigger battery like an 18650 you may as well get the most runtime and performance out of it too...the AW 2600 and 2900 mAh will do just that.