Brucegel:
There are good tube designs and bad tube designs. The same goes for SS. Each has its advantages and disadvantages.
As far as digital goes, I feel that CDs are an improvement over vinyl records. It's very hard mechanically to put the signal onto vinyl, and also very hard to retrieve it. CDs don't have those problems, so it's a "less imperfect" medium. The A/D and D/A conversion is where there may be problems, but I feel they're done fairly well, and better than the electrical/mechanical and mechanical/electrical conversion done in vinyl records. The electrical/mechanical and reverse conversion done on CD is less prone to problems because you're simply looking for signal/no signal.
Tape also has electrical/mechanical and the reverse conversions. It's at a smaller scale, but you're still doing it. There are problems with this. Digital tape is more able to ignore those problems because it's easier to do signal/no signal recording and playback. Again, the A/D and D/A conversion could cause problems, but it seems to be quite good.
I'd say that the case is less clear with digital vs. analog tape than with CD vs. vinyl record. Analog tape is probably a better medium than vinyl records. It just costs more to produce which is why it didn't dominate the market.
Getting back to biasing tubes, yes, you definitely want to make sure they're biased correctly. Tube equipment has added hassles that you don't get with SS gear, and that's the price you pay for using tubes. One would hope that the benefit to you outweighs the increased hassle.
Once you figure out how to do it, it's normally quite easy. You shouldn't have any trouble with it.
