Tough choice for a new setup, please look

Not familiar with most of the players you've mentioned but I've listened to CEC 51XR and previously owned the CEC TL-5100 transport. Well, in my opinion the 51XR as a standalone CD player is just mediocre and not too impresive but the TL-5100 belt driven transport top-loader sounds exceptional being paired with a good DAC. The CEC transport/DAC combination will outperform the standalone CD player by a huge margin IMO. Just make sure the DAC is a good one. Not familiar with the Altmann DAC so can't comment on that one.

I compared the CEC directly to the Saturn and much preferred the CEC. To my ears, it has a fuller, more natural sound without any loss of detail. It also has deeper, better controlled bass. Not that I don't like the REGA. I owned the Apollo and was upgrading when I bought the CEC. The CEC is built like a tank, much better than the REGA, and also has balanced outputs. In my opinion, it's also better looking, but obviously the posts show not everyone agrees. Overall, I think the CEC is a bargain, probably because the yen is cheaper than the euro right now and it's not well known. If your ears tell you to buy the CEC, I'd do it despite the REGA hype.