Shower headshaver here. By feel...mirror isn't much help (to me, at least). But the face gets shaved at the sink.
I once bought a fog free mirror for the shower and the stupid thing fogged up
I have shaved in the shower for years. I really don't like doing it in a sink. But I will if I have to. I have even done it inside a tent when I was going to one of those outdoor concert events and the showers were COLD!!!!!
But at home, I do it by feel in the shower. I have even done it when the power was out but there was still hot water in the tank.
Shaf, I think you said you are in the UK. I've found that in Europe, the showers are much smaller than in America. I don't think I'd shave in a German shower.
I think your right dude

Damn!! Funnily enough it reminds of me of an observation I had in the late 80s as a kid watching our saturday US tv fix (Roseanne, the Cosby Show, Alf!) that u guyz have bigger freezers on average than here in Europe! Maybe we've caught up abit on that front

But sir... we have bigger ...... er... errrrrrm ..... I'll have to get back to ya