Advantages of a tube CD player over an SS player?

tube cd player has tube buffer stage that pleasantly colors signal while one without tube buffer sounds newtral and more accurate.

There are too many variables involved to form any stereotypical opinions. There are "colored" tube players and there are exceptionally honest and pure sounding tube players. SS players can be colored just as much, just in a different direction/characteristics. I've heard excellent examples of both and poor versions of either. I'd focus on quality of analog circuit, power supply and designer talent/ implementation. In my experience tube-transistor differences seem less with digital sources than with amplifying components.
Charles,

tube cd player has extra tube buffer. the rest of hardware is just like in ordinary cd player. extra buffer implies to extra circuit elements implies to extra stage in the signal path implies extra colorations.
you can make any cd player with tube output stage. just purchase musical fidelity tube buffer and even pocket cd-player can become tube cd-player.

I agree with comments that a 'tube' CD player simply adds a tubed buffer stage.
Now all the tube parts costs money, the extra parts and a better transformer for the tube B+ voltage etc.
So the tubed CD player should have to cost more money for equal sound (in theory the added tubes stuff should jack up the price by $300 to $1000 for an 'equal' CD player)
I opted for a separate 'tubed' stage and bought a used VAC Standard four tube preamp for $1500 to use as my 'tube buffer'. Worked out great. And I can use it with an assortment of digital gear. Not stuck in just one CD player!
(I tried a cheap tube buffer which was worthless IMO, Where in comparison the VAC is really a great device)