I think this discussion is far too negative vs. the actual experience of the average JB light user.
I've had two of their lights, the E3P and the 3M. Both have performed fine, as advertised, and no QC or other problems.
Also their US-based dealer has been great, and from what I have been reading here (not in this particular thread only) has been very responsive with exchanges and the like.
There is the issue of JB operating on the bleeding edge of technology, offering broader spectrum electricity ranges, latest LEDs, programmability, advanced UI, etc.
This may indeed lead to issues with v1.0 lights. So people can choose whether they want to take a bit of risk for the advanced features, or wait a bit for the kinks to be fixed.
On the broader issue - how much risk can/should one accept?
Sure, this can depend on one's situation and job, and also on how many lights one easily has access to.
I tend to carry 1 in situations that are not risky at all, and at least 2 otherwise. If in a group situation where several people have flashlights, this too can be a factor (you need to carry no more than 2 in that situation unless there are additional risk factors involved, e.g., mountain climbing, cave exploring).
Really, there is no reason to fear JB more than several other similar companies. Even the SF legos many of us (including me) use a lot are not foolproof given that we are mixing and matching components from several sources (aftermarket, custom, clones, genuine SF parts, etc).
Risk will be there in all situations, it is a matter of managing it properly and logically.