2600 miles and no issues
Love it. Mounted to the down tube it affords much better handling than my old rack-mount battery. I charge up to 80% most times with the mini charger, and there has been no change in capacity as far as I can tell. I ride in Florida so the pack sees plenty of heat and rain, never had an issue there. I use for commuting to work, and I have about 25 rides left before the pack pays for itself (due to savings on gasoline).
Plastic case is too fragile / bad quality
The small plastic tabs that attach the case to the cradle broke one after the other, even thought I strapped the case to the frame using 2 very strong Scuba Diving Rubber Knife Straps. Keep in my mind that it is mounted on a city bike with front suspension (not a hardcore MTB). Luna's response to this issue was that I could buy a new battery pack. But in my view there is a design flaw, so the tabs would break again. I strongly suggest anyone to buy a different (stronger) battery back.