E3D obxidian high flow nozzle for X1C Lifespan

Hello all, wondering how many of you have used the E3D obxidian high flow nozzle for X1C. I have about 740 hours on my nozzle and it randomly plugged yesterday on some simple PLA filament and I’ve been unable to get it unplugged. Couple of questions:

1/ How many hours are people seeing on these nozzles before wearing out?
2/ Anyone have a condition where you were unable to unplug with one of these?