PS re-reading you post again JOe, ok, clarify, is you are saying, no, don't be happy, that no errors and great looking now. That fact that is had all those errors once, even once, for couple of days, means, trouble is coming... and you would bail.
I am saying the errors are real and an indication of something wrong in the hardware associated with the internal drive in your iMac. There is no question the drive will fail [b]all drives fail eventually[b]. The question is not IF it will fail, but WHEN will it fail? The S.M.A.R.T. and NVMe attributes that propose to predict failure are based on statistics which means they are roughly accurate within one standard deviation of the mean or about 70% of the time, but the others can fail anywhere from the next few milliseconds to some time in the next decade. So there is a 15% chance that your drive will fail soon and a 15% chance you will have disposed of the iMac before it fails.
ie, odds of it going another nice easy year or two is unlikely? It's not freak glitch,, maybe..? if reading that right... Software may say otherwise....? if have that right.
Just because a condition is intermittent does not mean it isn't significant or that it is not a reliable indicator of system health. Anything that would cause a CRC error is not going to go away. The odds are it will get worse. More importantly, it makes it more likely that errors will occur, perhaps undetected, and you won't know when they happen and therefore will never know when your last GOOD backup occurred, making recovery very difficult.
Of would take calculated risk and go with no errors and hope stays ok until: M2?
I hate to lose, so I am not a good gambler. How good a gambler are you? And remember this, if you wait for the M2 iMac, there will always be an M3 iMac just around the corner.
