erick - I understand what your were saying all along. I just thought some of it was incorrectly or at least confused. Let me explain.
Async usb is bit perfect, but so is reclocking. . You seemed to imply that aysnc usb it bit perfect but reclocking is not.
Upsampling is not bit perfect, but nobody would claim it is and it is a separate process from reclocking.
Aysync usb and reclocking as are good as their clock, assuming a quality implementation. Async usb and reclocking using the same clock should produce basically the same result as far as jitter is concerned. Once again, you seem to imply that async usb produces lower jitter than reclocking, which is not the case.
If you believe that async usb is superior to reclocking in terms of jitter, then we disagree. If you agree that properly implemented async usb and a reclocker are basically equal in terms of jitter, then we agree. All of this assumes a quality implementation with the same clocks.
As to why async usb is so popular, clearly it is better than sync. It has also become a requirement as far as marketing is concerned. It is also easy to implement. There is no reason not to do it these days. But, that does not mean it is inherent better than a good reclocker
in terms of jitter.
And, yes, I do understand async usb.