Ahh, tubes vs transistors. Have we all forgot Bob Carvers challenge, in making his solid state unit sound like a tube unit? He did. Its all in the transfer function and the output impedance (as Mark mep mentioned).
Preferences are another story, who can resist the sing song of a SET amp on certain kinds of low complexity music. Or, deny that a fine solid state amp can hold toghether during serious complex orchestral pieces. In between, these two amps can sound close, depending on music and speaker load.
Accuracy to the recorded source, well, as I have said before, plain old stereo (POS) is severly lacking in the believability department compared to live unamplified sound. It depends a lot on your expectations when you listen I think. Sometimes I want to hear details and sometimes I want to be hearing something akin to what I consider great sound, neither is accurate to live unamplified music (due to POS effect), but both are meeting my needs at the moment.
Yes, you can put together a system with a flat speaker impedance, and with say a push pull feedback tube amp and a solid state conventional voltage feedback amp and be damn hard pressed to tell them apart operated within their capabilities.
But, to say that any "competent" tube amp and solid state amp will sound the same, no. Can you make them sound the same by design, I say yes, if you specifically do want to do that. In that respect, the tube vs ss war was over when Bob Carver did his challenge, what, twenty years ago atleast?
Preferences will go on forever. And the real deal is the source and the output (anything that flaps about in the air)
Tom