[RC-Monster Mike]

Determining what batteries have accurate ratings and which ones don't is indeed the real challenge. Better batteries will yield better results(more cycles, more power less problems, etc.), but how does one determine what batteries to use?
Other people's experience is one way - Turnigy/Zippy packs get mixed reviews, for instance. Hyperion G3 packs get glowingly good reviews. Maxamps packs get mixed reviews. ETC. The list goes on and will continue to grow. Over time, the better batteries will show themselves with less overall reported problems.
Reported success and reported failures need to be taken with a grain of salt, though. Some people just can't or don't drive hard enough to maximize the system potential or to realize their battery's downfalls. The Zippy or other low end packs that work great for a casual user that doesn't use brakes a lot, or putts around at low speed is not indicitive of a safe and recommended setup for a skilled and competitive racer, for example. While they may appear to be a good value on the surface, long term results are likely to tell a different story. Over time, the better batteries will show themselves with less overall reported problems. I have seen more reported failures with Zippy packs, yet some people swear by them. No setup is exempt from occasional failure, either. Experienced users with premium equipment can have troubles, though it is going to be far less common.

I agree with Bernie(and posted a similar analogy some time ago) - if you want Ferarri performance, you can't buy Yugo batteries and expect good results for any length of time. If you run cheap batteries, I suggest leaving yourself some head room in the setup - gear conservative, minimize hard braking, etc. Most importantly...take your licks like a man(or woman) if things go sideways - all the money you saved on batteries can go towards a replacement controller. :)