I have a Miller 351 transformer tig machine (runs on 220 single phase) and find most tig videos are for the digital crowd and not much content on transformer machines.
I think it boils down to that you have so many fewer choices to make on the old-school units. Even on the fancy ones, it's usually pre-flow, ramp up, peak current, ramp down, post flow. With the odd other setting.
The hand skills are the same, though you don't have the options to pick through, as far as varying the frequency and all that. So you learn to deal with a lower current setting, for fine work, etc. <shrug> I learned on transformer machines, and that's what I have. As much as I would LIKE to have a new Inverter in the fold, it probably isn't the highest priority for me. Gotta get my wants and needs sorted. I WANT the $10K Miller unit, I NEED, well...probably less capability than I actually already have! LOL!
I get a lot out of Jody's videos on welderstipsandtricks channel on youtube. Unless he is showing what a particular machine can do, generally, his advice and experience applies to pretty much every guy trying to improve their work.