I've always lusted over the MacIntosh (sp?) line. I heard one once at a stereo shop and the difference was incredible. The difference between tubes and transistors can best be described as the tubes have a sweeter sound. Its a little more full and less harsh. However, they ain't cheap! But a tube based cd player is the height of retro!
I'm knowledgable about electronics through my job, but its not really one of my obsessions. However, I'm very picky about how things sound (more so than my budget will allow) so I guess the 2 overlap somewhat.
My latest project is to try to add whole house stereo, or at least get rid of the CerwinVega speaker/end tables. The house is getting kind of small with a 4yr old around. But in ceiling speakers are like $200 a pop from Crutchfield so I'm thinking of trying to use car speakers with paintable grills. The it looks like the specs are about the same and all I would have to do is some impedance matching.