I went in to town today, so thought I'd pop in to the local camera place and have a play with the X-T3 to see if it seems like a worthwhile upgrade from my X-T20 not.
I tried them both with the same lens (27mm f/2.8) so I could see the difference in the autofocus between them.
The X-T3 was much snappier, with my X-T20 hunting for focus a couple of times in the lighting they had in the shop, and the X-T3 hitting perfectly every time.
The eye AF was great too, had no troubles tracking the sales guys or other customers as they were moving around.
The body feels much better in the hand (in my opinion) and as small and petty as it may seem, the shutter seemed to be much quieter and nicer sounding too.
I also couldn't get over how much better the EVF was. I knew people had mentioned how much better it was in the X-T2, but I hadn't experienced it until now. It made the X-T20 EVF seem tiny and not very sharp.
Long story short, I'll definitely be saving for one, think it's well worth the money and should make for a nice double setup alongside my X-T20.