Transport Question

Bits are bits. If you accessed your banking data from a different computer would it change? No, of course not! Digital data, whether banking/financial or music, remains inviolate regardless of how many times it is transferred or where it is stored. That is the fundamental premise of Digital. The old Analog ideas do not apply! All transports and servers have to output the same data streams. Only audiophools believe that spending more and more on a transport/streamer gets them better sound quality. You should beware of the anecdotal claims made by the 'golden ears" crowd. Like the eyes fooled by optical illusions, the ears are also fooled - especially by sighted testing/comparisons.

Keep and use your Rotel, particularly since it is new. Unless you are so insecure/misguided that you absolutely must buy a shiny new toy!

don‘t know anything about the SIM, and you don‘t specify which Rotel you own so impossible to give direct advice.

Unfortunately transports do make quite a difference. Whether an upgrade will bring you tangible benefits commensurate with cost is something only you can find out by directly comparing your CD player with transports within your price range. Sorry no easy way out.

I upgraded to a 260D but can’t offer you an opinion relative to the Rotel as I haven’t heard it. The only ways you’ll get an objective answer is a) try the Sim in your system and a/b versus the Rotel and decide yourself; or b) hope that someone actually has had whatever Rotel you are referring to and the Sim 260D. Otherwise, it is all conjecture.

One thing you can reliably do is ignore the generalized better transports don’t matter narrative.

.

I too am in the "digital is digital" camp.   Assuming your transport isn't having issues, a different transport will result in no changes.   I think your money is better spent upgrading your DAC.  My DAC is the most expensive single component in my system.