I've not had too much trouble with them. Regardless of what they say they put out, figure about 600 lumens actual output for the cheapies these days. That's not bad for a < $30 light.

I have a Magicshine that's probably 5 or 6 years old at this point, a MS clone that's about 3, and a 2 emitter light from last year. None of them has given me any trouble, used daily all winter.

The batteries tend to start tapering off when they're about a year or two old for me, the 3 hour runtime goes to 2, then I start using them as backup batteries to keep in my bag, running them through a single 50 minute commute once in a while to keep them alive

This summer I bought a Cygolite Metro 550 for a front daytime strobe, and I thought I'd maybe use it as my primary nighttime strobe come winter, but it's already not making me happy. Seems like it's ALWAYS low on battery, I guess I'm not used to a light with only a 90 minute runtime, that means I have to charge every day and it takes 6 hours to charge. I think it's going to be my daytime strobe and nighttime backup for the eBay light that will continue to be my primary.