I've loved all my Naim CD players - CD3, CDI, CDS, CDS2, CDS3 - in fact they are the only serious CD players I've ever owned.
Unfortunately, as many have indicated, they are very hard to service because of the unavailability of spare lasers/transports. Normally the electronics themselves are pretty reliable but almost all my players have had laser/transport problems that could not be satisfactorily addressed.
I got a 10 year old CDS3 around 2013 fully prepared to deal with repairs given the age. Sure enough it started giving problems shortly later and after unsatisfactory repairs, I opted for the expensive full replacement laser kit from Naim which involved changing the entire transport plus the motherboard. My CDS3 made wonderful music for 6 years but now it has just gone to the technician again. I don't have high hopes.
I don't fault Naim for being unable to support their old CD players. To be fair, they have tried to keep laser transports in stock for as long as it was feasible (I understand they even kept refurbished old ones when new ones were no longer available). The problem lies with the structure of the optical player industry. Most hifi manufacturers rely upon mass produced CD lasers/transport because these things depend on economies of scale to be made at reasonable prices. Imagine, even very expensive high end CD players are built around cheap laser transports that are also used in very cheap players. Even the Rega Isis I believe is using a cheap Sanyo laser. And these things go obsolete fairly quickly as models are changed and updated. Unlike cartridges, different lasers and transports are not easily substituted.
I only have the CD3, CDS2 and CDS3 left. I am now using the CD3 because it's the only one that works (most of the time). My CDS2 is a doorstep and my CDS3 is a likely candidate too. I have no choice but to contemplate an acceptable cheaper player that I can just ditch if it dies. I no longer will pay a lot for a high end CD player.