bitflipper
It stands to reason that a 64-bit audio engine is going to better than a 32-bit engine.
Unfortunately, there are many things in this business that seem entirely reasonable, but just ain't so.
I would challenge anyone to create a musical snippit, exported with and without the 64-bit option, that even golden ears could distinguish in a blind test. That includes you, Freddie. Post two clips that differ only in whether or not the 64-bit option was enabled, and see if anyone can identify them in a blind ABX.
But it's not as though the option does nothing at all! Here's what the 64-bit export option does for you, in a practical sense: you get to use double the RAM when you export.
I agree with you bitflipper regarding the test to distinguish the difference. But I stand by my statement that you quoted above, somewhat out of context.
Mathematically there is no denying that a 64-bit engine is going to more accurately process the algorithms that occur within your DAW software over a 32-bit engine (the boundary case scenario being that there's not enough information to warrant a numerical difference, in which case the results would be identical).
I know you know that because I can tell you are a smart bloke. You picked up on my inference that the audio would sound better whereas the point I was trying to make was that there is a difference and, whether you can hear it or not, why worry about it if your system can handle it.
The only time I think you should be concerned about whether there really is a difference is if your system is not able to cope, in which case drop down to 32-bit and you probably won't notice anyway.
So, in summary...
If you have better gear or better options t
hat don't impact your workflow by using them, then, well, use them. Regardless if you can really tell if there's a difference.