i have the turnigy 400w chargers, got a single and a double.
running on a ripmax power supply, the double will happily charge a pair of 14.8v packs at 10a.
the only urk i had was fan noise, but i opened them up and just put some anti vib grommets between the fan and the case which made a world of difference.
i'd agree that there are probable better chargers, but for the price they're very very hard to fault imho.