I've had four of them in an old Marshall 4X12 for about 6 months and haven't had any problems yet......*keeps fingers crossed*
If one of them went out in a 4X12 being powered by a 100 watt head would I notice right away or is this something I'd have to listen closely for and then notice when my head blew up?
I don't feel an urgent need to replace them at this point and love the way they sound, switching to celestion greenbacks is not something I'd be looking forward to at all (mainly due to the $$$ not anything against Celestion).