I finally caved a couple of weeks ago so am in the experimental phase. The answer to your question is it depends on what you like to eat and what you don't do because it is a faff having to wait for the oven.
What I have found out so far
The roasted chicken you see variations of on S M is lovely.
Roast potatoes are quick and lovey
Light things ...eg breadcrumbs need nailing down.
Food does nothing for a while and then it is done done in the blink of an eye
Write down what your start settings are and then you know what the base line was for tweaking it (or not) was last time
It is brilliant cooking the beige buffet things the kids like & prevents them leaving the oven on all day.
Jamie Oliver's air fryer recipes are good... Shame you have to put up with his Mockney Lad bluster and fat fingers bothering the food to watch the videos.
It is great for cooking for one or two people without having buckets of leftovers. Super useful for when you have variable numbers at home.
I have been told that you should reduce temperatures by 20/ 30 DegC and cooking time by a third to convert traditional recipes to air fryer ones... I have yet to test this.
Cleaning is super easy - I have the Ninja Dual.
It is not quite big enough to take a half baked baguette from Aldi... I have to cut a small bit off the end of the stick.
So far I think it is worth it... Is it life changing? Not yet.