I am very happy with my G30s and I received excellent service from Line 6. I have to say, the most important thing is that it works well and I can only report the best there. The sound is excellent and the G30 system never failed me.
The only issue I had with firmware was with the oldest first generation model. I had interferences with my wireless network at home and I could not update the transmitter's firmware. But as I said, Line 6 provided me with a replacement at no charge (thanks Line 6) and since then all works like a charm and with the more recent firmware there is no more any noticeable interference with the wireless. BTW, that interference did not impede the G30 but made weak signal computer connections entirely unusable. When I rehearsed, my wife couldn't get on the internet anymore from her corner of the apartment.
Moreover, if you get a new G30 system these days, I am pretty sure there is no issue with the firmware and all works right out of the box. That was at least the case with my 2nd system I bought. And in case you really do need a firmware update, it can be done at any good store and is a only "once in a lifetime" thing rather than anything else. I find it rather good that you can update the firmware, even of the transmitters. All in all, I can only say the G30 is an excellent wireless system, which I can only recommend. As I said, works reliably and the sound is excellent.