I've had my experiences with my initial purcahses from FDM when I was first learning about brushless.
All I can say is that I bought 4 of the 2S 3700mAh lipos from him and I almost s**t myself when I discovered that when they were a year old 1 of them puffed just sitting in storage. About 2 months later the other 3 packs all puffed the same way. Needless to say that was about $500+ down the drain.
I've never had any other lipo puff up on me like that (and we're talking owning TP, Kokam, Orion, TrackPower, and MaxAmps packs).
Just as a side note - I read this about a puffed or vented pack somewhere - it said put the pack in salt water and put a knife through it. They didn't happen to mention how volatile the chemistry in the lipos really are. When I put the knife through the pack it literally melted the last 1/2" of the knife to the point where it looked like it came out of a blast furnace.
After learning my lesson, all I can say re: FDM is - "JUST SAY NO!!!"