Ok, so, I seem to have actually started a full blown argument with my IRL guitar friends over this (there are some strong personalities) over whether there is a “best” tone to practice with. So I thought I would see whether you guys can be the voice of reason, or put forward some new views 
In my experience, I seem to get the most out of practicing with a tone that would be classed as crunchy, but unforgiving. I don’t want to sound good when i practice, instead I want to hear my mistakes. I make sure that there is just enough gain and comp to make sure that I can hit pinch harmonics (but only if I nail them) and that it has enough sustain and gain to carry legato licks etc. Oh, and a tiny bit of reverb to make it not sound totally poo.
If I have it set cleaner, I find I don’t hear muting mistakes, and if I have more gain, I find I miss inaccuracies that the gain covers up.
Thoughts?
N.B. There are no wrong answers, only opinions, I’m just curious.

) but there was also a strong sense thst a simple medium shows you your skills and allows you to practice honestly.