Mine has been up about 2 1/2 years now without issues. Well, wait. I did have one issue with by EB832. The internal power supply went bad. Truth be told the back story is this though. Car hits power line. Power line starts fire. Fire spreads and catches the other pole on file. Fire fighters put everything out. Lad in car is safe (no idea how they pulled that off but never the less everyone is happy). Utility company restores power. Utility company has a issue in the process and their redundancy of something fails which then sends in 3 times the expected power into our neighbourhood. A surge like a tidal wave.
Probably 200 or so homes in our area as we are on the outskirts. Anyway wave of power hits, trips the main an all of our homes. Some are safe and sound - probably the furthest away from entry point. Those of us closer or unlucky, well, blown solar inverts, appliances, stereos, smart switches, and of course EB832 energy bars :)
So yes, I had a failure. Unrelated to Neptune but rather freak accident. I guess I could have plugged it into a surge protector or as i'm doing now installing a whole home device. In either case outside of that no. In fact I sent that one in for repair and now it is a spare :D