I noticed on another thread that cchris2lou had recommended some £28 light as all you'd ever need, but the instructions said always charge the batteries in a safe place, never overcharge the battery and never leave the battery charger unattended, which sounds to me like all you need to burn your house down!
I also have one of those, I had read the stories and took the risk anyway. As you say if they are enough to put you off go for one from either of the above UK sellers. It is a fantastic performing light and I'd buy another, though I'm tempted by the new offerings from the guys mentioned.
I've a couple of the 5W cree ones as well, they are fine for on the lit roads at night but struggle when there are no street lights. I wouldn't think having 4 of them would help either tbh. Good as a commuter but if its offroad riding I'd stick with some a bit more powerful.
At present I commute with two of the torch bar mounted 5w ones supplemented with a helmet light. Sometimes a 1000lumen torch and sometimes the 1400 lumen cree light. Off road I have a 1000 lumen torch on the bars and the 1400 lumen cree on the head. The Cree light also has one of the diffuser lenses, it can be a bit spotty without.