I used a mini for almost two weeks before moving back to the 10.5. I didn’t use the 10.5 once in that time as I was waiting for a warranty replacement.
Two things I’ve noticed. Confirms my love of the iPad Mini as a book reader. Reading comic books however feels better on the 10.5 to my eyes. Secondly I’d forgotten how great Pro-motion is for both scrolling and writing with the Apple Pencil.
I’m missing the smaller form factor of the Mini. I think I’ll look at picking up a cheap one used just to utilise it as a reading device.