I've been using Lipos in my helicopter for a year and i've had no dangerous acciedents with them. I did get one to puff up when i dumped it too much, but that was it. Spend some cash on a good charger and like all battery chemistries treat them with respect and they'll reward you.
Go to
www.batteryuniversity.com for some in hard core battery chemisty lessons and some insight into the mystery of the 'rechargable cell'