Engineer Justin Cortelyou has been working with legendary producer Bob Ezrin for many years. He talks about this (and more) in an interview with Tape Op Magazine:
He's seen enough, and he will put the fear of god in you. If you can make it through the boot camp stage with him, it prepares you for so much. You can take anything. But it's great, because it saves time. You know exactly where he stands, and you know if he's not happy. When the red light goes off, he's the best guy ever. He's not mean, necessarily; just intense.
On recording Phish:
We're used to cartage guys with little box trucks coming in with gear, but Phish bring in an 18-wheeler, and it's a huge set up. They have two instrument techs with their own benches. Phish also has their own engineer, Ben Collette. He knows their sound, and knows what they like. He's awesome to have – he has everything organized. He took out all these mic pres from their console, so we had a ton of great gear to use.