Well, I haven't changed the firmware, based on the bug reports I've been seeing. But to answer your question as to why I would, for me, it is almost entirely the built in dictionary. Since this reader is to be for my 11 year old son, I really would like that feature for him.
I also think that there are a lot of us tech-minded folks that like to do stuff just because we can/wonder what will happen.
I know that the Jetbook offers more language support than the Libre, and that may also influence some people's decisions.
I'll be watching this thread with interest to read the replies!