I had assumed that the hot battery issue was overblown after
@VGOODIEZ weighed in. But if the batteries are really getting that hot through regular use, for whatever reason, that is a very bad sign. At best it will shorten the life of the (replaceable) batteries. At worse it is a serious safety issue.
I suspect it is heat from the bulb warming the batteries. If the batteries are getting hot on their own, that would signal a dangerous short.
Anyway, I look forward to hearing if the batteries are getting hot enough to burn when we see some more out in the wild soon. And 2-6 months of use should show how reliable it is.