For the price you pay, the Saturn-R CDP will be hard to beat.
You may be better off using it as a transport, with an outboard DAC.
Or, if the laser is going out, buy a Transport and one of the great modern DACs available.
Upgrading a Rega Saturn-R
I can’t complain, but I also know that sometimes a new component reawakens the senses. I recently upgraded my Rega Aria to the Rega Aura MC preamp, and it closed the distance to the soundstage by half. Pretty incredible. Good records still sound more organic than the digital source. A 1970s pressing of Mary Poppins (don’t laugh!) is more cinematic than the recent high-resolution re-release of if in digital form. My mate (not an audiophile) can identify the source with her eyes closed.
So, what’s a rational upgrade for my Saturn-R? One can find the Isis (IC not valve) used for around $4K. But there are a ton of options once you get to $4K for a CD/DAC. The Isis is limited to USB 44khz digital input... that’s a downside...
Other gear in the chain: Rega Osiris amp; KEF Reference 3 Meta speakers; Chord interconnects.