Since then, in pursuit of specific guitar playing skills that I should have picked up when I was much younger, I've been buying big amps that "hold the note" in a particular way.
This is a point that deserves discussion, because among the interesting things that distinguishes between amps is how they handle the ADSR envelope of a note and the way it compresses - both of these factors play a big role in 'holding the note'.
I think about tube rigs a lot like how I think about analog synthesizers. The guitar is an oscillator with some first-stage filtering and modulation, but the amp is the second stage of the synth's parts, i.e., the filters, the envelope generator, the output modulators and other bits, as well some of the effects (reverb, compression, distortion, etc.).
When people talk about 'forgiving' amps, they're basically referring to the amp's ADSR envelope. If it's got a slower ADSR envelope, with slower attack/decay/sustain/release times, most players will refer to it as forgiving. The envelope varies as the amp is pushed into overdrive, so how it handles that is also of interest. The amount of compression affects the ADSR envelope, too, but also does something with the frequencies that get emphasized, enhanced, etc.
An amp that's forgiving suits a lot of players well, but it's always a matter of degree and trade-offs. An amp with a faster, more percussive attack with faster decay and release times is suited to different styles and players, and of course there's everything in-between.
I've yet to find an amp that does everything. They've all got their quirks and tradeoffs. They do different things.
Then there's the whole issue of touch-sensitivity, and you can throw clarity, ability to have all the notes of a chord come through clearly despite the overdrive, and frequency response, filter resonance, etc., into the stew.
Like you, I prefer 50W and higher amps, generally, though my DG30 performs more like a high powered amp (and it's loud as all get-out when I want it to be!) but in any case, big amps tend to have clearer, tighter (some call it piano-like) bass, and more clean headroom. Again, there's a huge variety among different amps rated with similar power.
Maybe all this is why I don't care for digital modeling amps. Synthesists know that analog synths, and digital recreations of analog synths, sound different. If my analogy holds true, it's simply an inherent result of the technologies at work, at least at this stage of the game.
Thanks to your discussion, I guess I'm answering the question posed in my original post!
