Because i work in the Audio Production/Music world, i was in two minds about joining in on this, but what the hell
A CD by nature is a 44.1/16bit medium, and is uncompressed. Meaning that its easy to rip an uncompressed WAV from a CD and loose nothing, however, depending on the encoder you use, your going to change the file bit for bit.
Vinyl, by nature, has an infinite resolution, unlike CD, so the potential for more 'stuff' is there, but often the high and low end suffers due to the physical real estate found on the vinyl. Next time you listen to a record, notice how the ballads are almost always near the end of the side, because there isn't as much dynamic range/excitement in them compared to other songs, ergo, they take up less physical space on the pressing.
But yeah, i agree, most people won't tell the difference between well pressed Vinyl and a CD. Unless you are sat in a good room ( far more important than the system you are listening through), and thought a fairly decent transparent system.
As for Valves vs Solid State, there is arguments for both. Well designed solid state stuff can sound as good if not better than a valve alternative, but a lot of people like valves for the 'warmth' etc, which at the end of the day is just distortion.