Ah good question! Firstly, I would CRY . Then, it depends on what I was trying to achieve with the music. If I'm just playing classic traditional blues rock or something like that, I would still choose the valve amp even if it didn't sound as good... I know that does sound deluded but hear me out! It would be because if my heroes who originally used those amps could inspire millions by working creatively within the limitations of that original equipment, then I should learn how to do the same. I would try to raise my game by improving playing technique, refining amp settings etc... to get as good a tone as possible, within the limitations of the equipment. But! If I was playing in a less traditional setting, maybe an originals band where I'm being more experimental and maybe trying to get synth sounds from the guitar, creative use of pedals, playing the guitar with an electric razor, anything like that, I wouldn't have a problem using a solid state / non traditional amp if that's what did a clearly better job and got a better sound. For the record, I have done some gigs just running through a multiFX with amp modelling direct to PA with in ear monitoring. It's weird and feels pretty lame compared to a proper amp, but in certain situations there's just no other option. I've done it with a wedding venue that insists on no amps on stage for noise restriction reasons, and an amp modelling setup is great as a compact backup solution. I just think if you have a choice between the real thing and a copy, go with the real thing whenever possible, even if it's less convenient and more difficult to work with, it will help you develop and work within limitations.