AI for editing is garbage. Chat to it to get ideas maybe, but in its current incarnation it’s just going to degrade anything you filter through it.
I thought it's quite good. Of course, I'm not taking 100% of output, but it takes care of my grammar blindspots (damn you commas and a/an/the articles!). Can you please share what and how gets degraded? Sometimes I don't like a phrase it selects, but it's not common
(Of course, that may well be exactly what you're looking for if you're writing an audit report or something.)