I'm using a pair of bridged 275s on my Everest 67000s and I've been very pleased with the results. I had a little bit of worry beforehand about whether they would handle the demands of twin 15s but the proof is in the pudding. Even at painful volume levels when prodigious amounts of alcohol have been present, they have kept the bottom end completely under control and at those volume levels, there's still no harshness in the high end, thanks to the tubes. And they are completely silent. I have considered going to a 452 and saving a little dough, but why take a chance? When choosing against a 452 makes sense, something is very, very right.