The last time I used my '67 360, with 80's high gain pickups in a "high gain" situation was last year. It was through a Digitech 2101, using one of the high gain presets (I think it was charmingly called "pimp life", but I don't remember the number) The Digitech was feeding my 70's Marshall "50W lead" combo ( 2X12 celestion green backs, open back cabinet, EL34 power tubes, not the 6550's that were shipped in the American version at that time) The room was a high-roofed warehouse, about 250-300 people. Volume was approprate for that size room, very little guitar in the PA but drums and bass were. I was a good seven or eight feet diagonal from the amp, with my back towards it. The GSP 2010 has a noise gate that was set low enough (I think it was around -60 db) that, once activated, the gate would not cut-off unless I damped the strings with my fingers. On the same bill, a friend of mine was using an F-holed 1966 330 with toasters, and it fed-back quite badly, but I had no problems. I think it must vary considerably from rig to rig and intrument to instrument.