well, seeing how the head is £40, id say it is cheap, colour casts that vary, inconsistant power output and slow recharge times. couldnt see what fitments it takes, so they could be limited.
basically you get what you pay for, but i would rather go for a named brand here in the uk where i get a warranty i can use if needbe. might cost me a couple of quid more, but its worth it.
i know gary edwards reccomends the lencarta kit, which he says is very good, and i believe him in truth. and there kits arent too badly priced either