True. He said he used an Analog Devices opamp but wouldn't specify which one. Not sure if he is using poly caps or if it is just an opamp swap. Maybe we can get an owner of a busman modded unit to take a quick peak inside and let us know?
One would be able to determine the opamps used pretty easily by just unscrewing the outer case. Determining if poly caps of some sort are used is a bit more involved as it would require complete disassembly of the unit.
Regardless of whatever opamps are being used in his mod there is more that goes into deterring if something is "better" or not besides a basic opamp. Power consumption, signal to noise ratio, detail, noise floor, etc, etc, etc.
I would be curious to know exactly which opamp he is using though.