if it's not fixed with freshly charged batteries, then PB support is totally awesome, they'll sort you out.

not like cygolite support, which kind of sucks.

i haven't dealt with moon or serfas support, but after having problems with my hotshot i'd suggest pairing a PBSF-turbo with a moon shield or a serfas TL-60 "shield". those two lights are the same light just branded differently, the light seems to be comparable to the hotshot, and the support can't be any worse than cygolite.