I updated to A12 and I am able to see some differences.
1. I've got 5g, volte and vowifi finally (5g on scnd SIM slot)
2. DPI is messed up in certain apps and options.
3. Battery life is worse (but I've been using stock kernel on A11, so this could make a difference)
4. I like A12s way to grant permissions.
Was it worth update? If you like your phone up to date - yes. If you care about system stability and look, stick with A11 until fixed A12 shows up.
It's not a coincidence that OP suspended A12 update. They see it was not ready.
My phone is OP 9 pro EU version. Did wipe it after update.