I've bought LiPo packs, chargers, and cables/connectors from them and have been very pleased. I think I saw a review of some of their 2.4GHz radio systems, and they were found to have poor intereference rejection when compared to the name brands (Futaba, Spektrum/JR, & Airtronics). In general, they have some very good stuff, and some very cheap crap. When buying from them I'd recommend the following:

[ul][*] Read all reviews on their website for the product you're interested in[*] Check here on RCU for reviews/feedback on the product[*] If you can wait and order 1kg+ worth of stuff, it's only a few bucks more for EMS (express) shipping. You get your stuff in a week instead of 2-3 weeks.
[/ul]