If the DAC is the same, how different do CD transports sound?

If you embrace the influence of expectation bias you can appreciate that the more you spend on anything the better you will think it sounds. That always works.

I am not aware of any compelling explanations as to why this might be the case, but in my experience, top-loading transports which utilize weighted pucks on top of the CDs sound better than other designs.

No confirmation bias involved in my observations, though I have never A/B tested.

I have had different transports plugged into the same DAC playing the same CD.  Mostly I compared by switching back and forth but one time I enlisted my (very bored) wife to do the switching and write down my impressions.  My blind impressions always corresponded to my unblinded, but unless I get a different lab assistant I won’t be doing that again.  At any rate transports matter, imo, but the DAC is still the major determinant of digital sound

I think the differences are more about build quality, features, and the ability to read cds ie error correction, buffer etc. I’d like to think my McIntosh transport sounds better than others, and maybe it does, but it can read cds other players can’t and it also has the ability to accept and play dsd files from a USB thumb drive. My two cents.