You've likely seen the air fryer commercials with the excited salesman and the eager and supportive female shill, no?
I've been curious about their "claims" since watching the first commercial. I then started deliberately watching some of the l-o-n-g infomercials wondering if any of it was true.
So, before Christmas at a party the hostess had several veggie and sausage dishes made in an air fryer, and others at the party had them and I was impressed with them. Did the stuff have that "finger lickin' good" flavor? Nope but good enough to get an entry level model @~$99 for my GF.
The "cook book" that comes with them is really just a pamphlet, and I found most of the cook temps and times could not yield decent meats or chicken. OTOH, veggies were pretty straightforward and if you watched them closely and diddle a bit with the time and cook temp till you got the hang of say french fries they turned out excellent if you flip the contents often enough for an even cook consistency across the batch. Mixing sweet potatoes and Idahos are a different story. Start the sweet ones well before dumping in the Idahos and you'll save time.
Meats and fish are more of a hassle to get right. but I liked the results enough to get an "XL" sized model during the after Christmas sale.
Following the cook pamphlet (or "dashboard" recommendations) and getting that golden fried look AND having meat or fish come out anything resembling the informercials will not happen, that is unless you experiment. Also the commercials lead you to believe the air fryers are a set and forget machine. Nope, air frying takes about as much effort as frying in oil BUT it does take less time.
Most of them recommend start and finish temperatures too low. A "LIGHT" spray of cooking oil on breaded chicken and playing with the highest start temps (400 degrees the highest they go) for the first (or last actually) portion of the cook time (say the first/last third) and lowering/raising it to the recommended temp for the rest of the cook time will get you a nice finished color. Regular turning and moving the meat around the basket will get you evenly cooked and juicy meat.
Once comfortable with veg and Chicken, fish are less of a problem but experimenting with time (generally less than recommended depending on fillet thickness) and cook temperatures will get you some good fish.
Quality
You get what you pay for. The smaller models may have what looks like a stainless grille pressed into the basket. These are a chore to clean.
The XL model I bought has the cook "basket" made of one piece perforated metal, this type cleans up in a few seconds. Add to that your stove / cook area stays clean without oil splashing all over the place and there's very little if any sticky vapor coming out of it! They're great for busy (or lazy like I can be) people.
Spoiler alert!!!
Meat and fish simply will never (IMO) be as good as greasy fried food, but I find it satisfying that I'm no longer glopping greasy meat down my gullet any more.
On a similar note I am using a microwave bacon maker (the type with three "T" type hangers) for years now, and the bacon is every bit as good as fried, just less greasy, but they are a PITA to clean.