Older CD players vs current ones?

Regarding SFCD-1, Linn Karik-numerik, Sony etc.. and some other dicontinued CDP's. How would they rate against newer models?
I have Karik II (stand alone CDP), and preffered it over Genki. Also, Karik is exeptional transport, so if i want to ad on Numerik,(or any hi-end DAC) i would probably end up with as good as digital source as any. Even by CURRENT standards!
I also have an older cd player as well as a great transport in the Sony X77es. I am not using an outboard dac as of yet and the sony seems to sound just fine as a stand alone player. You might not get every little minute detail out of a recording because the dac may be a little dated, but you will get close without refinancing your house for that super duper dac. I can say this about the x77es. When I try to sell it, I get a lot more responses for this player than any of the newer models that I have had. Being that it weighs 40lbs, I think audiophiles know that some of the older equipment was built to stand the test of time. I think the only drawback is putting the newer 24/96 dacs with the older players. I guess you won't hear the full potential of the dac if it does'nt have the newer output of some current designs. The sony retailed for 1700.00 dollars in 1990. I saw a 77es for sale at audio outlet and they were asking 895.00 for it. You can't find that kind of a return on year old equipment now a days. The sony, as well as a few of the older players ,can still hold their own cosmetically and sonically today as they did 10 years ago.
I'm baffled that several Rotel dealers (apparently even a factory rep employee) admitted that the old 855 sounds better than the recent 951, 971 series! What's going on here? I understand the newer transport's cheaper-Asian, but aren't newer DACS supposed to swamp 10 yr old ones? So far I prefer my 855 to an ARCAM 9, Audio Refinement, and, in some ways, to the Bel Canto/DVD setup IN MY SYSTEM! Don't get me wrong...I still think the top end is insufficiently resolved, but it's clear that the road to improvement is not simple! Happy holidays to all.