I got the 2020 12.9. I really cant fault it. Ive had the 2017 version since it came out (will sell it once lockdowns over) but as it’s only 64GB I kept running out of room. I also wanted better connectivity as well so got the 128GB one. I was sceptical about face detection when it first came out but love it on my iPhone XS Max. Its a nice improvement over the finger ID of the old one, although its not quite as reliable as on the phone. Due to where the camera is placed it sometimes takes a couple of goes. I don’t think I’d like to go back to finger ID now.
If it wasn’t for the extra storage i might not bothered just yet, its better but not amazingly better. Some of the features I already had, like the screen is the same. It does feel a lot nicer in the hand though. Its more like a slate if that makes sense. And of course smaller than the old one. USB-C makes life a lot easier as well. No more need for adapters (we have loads of USB-C gear already)
I suppose the pervious model would have been the more cost effective choice, but at least I’m future proofed for a few years. I dont tend to change them too often.