I have a Steelcase Leap V2 ($300 refurb) and it has two advantages over the Aeron in my opinion.
1. It’s much more adjustable so you don’t need to be carefully about buying the exact right size (unlike the Aeron which has sizes A, B and C)
2. It has a fabric seat with no protruding edges. If you sit cross legged on an Aeron, you’re going to grind against the seat’s edges. Aerons aren’t good for folks who sometimes sit cross legged.