Also got a Ninja one, but we got the thing with dual baskets so you can optionally cook two foods at different temps. Really makes getting those tendies and fries much easier.
I got some $15 one from bestbuy 8 months back I think and it gets used almost every day. I haven't turned on the oven in so long I wonder if it even works...
Biggest disadvantage is that you have another bulky piece of equipment taking up counter space. Best option is to get a convection oven with an air fryer setting. It's even more convenient because it doesn't take up additional space and you don't have to move it in/out of storage. It's always there ready for immediate use.