I replaced my mid-2017 21.5” iMac with this one after the logic board went south on me. I totally got robbed when I bought the 21.5. It was so slow I had to purchase an external drive to boot from using an SSD just to get my boot times under 6 minutes. Yes you heard that right. 6 minutes.  Maybe it was the logic board the whole time?  Don’t know.  This used Mac is way faster and way more responsive. Internet speeds match what I should be getting as well (500mbps+\-) vs 100mbps on the former.The only knock is that the description said this unit was in excellent condition but it was not. There was a deep ding/scratch on the back. But, I can live with it since it’s up against a wall and I’ll never see it.So far so good. It’s a nice upgrade from the 21.5” and a larger HDD.