I prefer the tube amps in all things bass and guitar...
That said, I like different end results from these two groups...
For bass, I want strong and "MOSTLY" clean, gutsy, chest thumping sound. Not so much interested in overdrive or distortion, though both are inherent in small amounts anyway tube circuits. I can get overdrive and distortion in a more controllable way from pedals. I just want a tough, powerful delivery.
For guitar, the saturation of the transformers, power tubes, overdrive and distortion mean a lot more... I want the amp to be the source of overdrive and distortion, and have it controllable by how hard I push the amp (hit the string) - clean to overdrive in one "arpeggiated" chord, so-to-speak...
With bass, I like how tube amps presents the sound. Tube amps are "tuned" or "voiced" to deliver a limited frequency range that will compliment the instrument. As opposed to SS (my 2 Edens come to mind), which simply deliver the whole audible range of 20-20,000 hz. I also like the sound a transformer adds to the tube amp's sound. There is a dynamic quality to the tube amp's components I've not found in solid state amps. It is this difference that means the most to me, and has 'til recently, kept me firmly in the tube/transformer camp.
However, with age, I'm now more interested in getting the tube amp sound from a much smaller and lighter set-up. I've found a couple of amps that do the "Tube Thang" brilliantly, but without tubes or big heavy transformers! One of these new "discoveries" has more "life" to it than the other, and makes me believe I'm hearing the heavy iron transformers and power tubes of an SVT, or Traynor, or Fender PS400 - a large, heavy tube amp in other words. It's a kind of psycho-acoustic effect that I'm glad has fooled me. 'Cause, 'til now, I was stuck with amps weighing in at 65 lbs or more!
Welcome to the madness!!! And I hope you enjoy your tone journey as much as I have!!!