I think the biggest scare for a lot of people is the amount of horror stories about them being dead on arrival or problems with flight. Seems to be a quality control issue.
I bought mine second hand and flew without a single hitch on every occasion so I can only look at it on the basis is there must be a proportion of owners with working systems vs defunc ones. For the price, I think that is where the dissatisfaction comes into play.
In relation to the battery, as mentioned it is not out of the ordinary for those times considering how much work does into keeping it in the air, providing a video feed whilst tracking it's position. It's short but enough time to fly and enjoy yourself.
Only downside I find is it is pretty fragile so considering it's designed to be airborne, may not really take much damage before parts need replacing.