Well I am still amazed at the battery life. I'm getting around 70K J on the Q same battery on the M around 28K. This thing is amazing. Somehow I am getting almost 2 1/2 times the battery life on 2 HG2's. I don't know if this board has something to do with it or what but I was expecting about 1 1/2 times getting way over that. They did good with this one.
That would be my guess as well. I've heard the Mini's weren't overly efficient. In general buck circuits are more efficient than boost. Since the Q has two batteries in series, it's most likely always bucking voltage so you are probably seeing more efficient results. I don't have them to run tests, but it sounds like a reasonable theory to meI'm getting amazing battery life too. I think the 450 board is more efficient than the 350 board.
Cheers,
Steve