I am hoping to order one of those two later this next week and am wondering what the differences and pros and cons are? I am looking at the M3 multi-reticle btw. So far as I can tell, the M4 is AA powered and as such offers longer battery life. Is there anything else I am missing? I like the canted mount of the M3 better and will go with that one if there's nothing really extra that the M4 offers besides the battery life.
Size and weight. The M3 affords more mounting options.
Wow, to be honest I had never even considered the weight to be different. I think I want an M3 because at a later point I can get much better mounts if needed.