I’ve gone from a 7 to 12 mini, and it’s been great! Upgrade in photo quality is the main benefit (especially at night), but I like that it’s slightly smaller, and I was constantly hitting the storage limit on the old phone.
Face ID is much better than I was expecting, works well from a variety of angles and distances, and either with or without glasses on. Mask thing is annoying, but hopefully that’s a relatively short term problem.
I did make the mistake of not putting a screen protector on straight away, and now have a scratch on it; apparently their new glass is more shatter resistant but softer!