Yeah, the higher initial voltage might be a concern, and the 850mah is kinda low, but that's just to keep the weight down. I have been using a 2s M1 cell pack for about a month now, I am getting quite a few runs out of it between charging, at least 10 I think, and nothing has gone wrong yet. :) So the capacity isn't that bad, if you don't mind recharging an extra little pack every 5 runs or so.
I got this batt just because the BEC shutdown on me at the 20 min mark in a 30 min main, cost me 2nd place, if not 1st. This obviously is not for everyone, but it's a good alternative to anyone who don't trust BEC's anymore... Brian?
Also, Hyperion says they work in all applications that a normal NiMH rx would, so you don't actually need high voltage servos, or higher quality units. I bought the 7955 as well, so I am sure it will give some decent twist with one of these. :)
BTW, thanks for posting Mike. :)