Ninja
Foodi Dual Zone Series
Dual zones for smart cooking, but baskets are small.

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The emeril lagasse 360 French door is amazing. It does everything, even rotisserie!
I got the emeril 360 French door air fryer toaster oven. Solid stainless interior, does a lot of things even rotisserie. The basket and wire are stainless though I think the sheet was some kind of aluminum but I ruined it in the dishwasher. I just bought all stainless steel replacement/extras on Amazon. It’s a pain to clean and takes 4 minutes for toasts but otherwise I love it.
Second this- switched from our place and replaced the tray with stainless steel also
I love my InstantPot Pro Crisp. It does all the things an InstaPot does and has an air fryer attachment. I needed a new toaster oven because mine just died, so I got an Emeril French Door 360, which also has air frying functionality. We'll see which one I end up using the most. I love the InstaPot, but I literally have to switch out the top as that's where the air fryer is vs. this new one, I'll just need to load the food in and tell it to air fry. I just got the toaster over replacement, so time will tell. I still have yet to wash all of the different trays that come with it to use it. But I'll test run it later today with Trader Joe's brand tater tots. I'm not sure why, but with that brand I found I have to adjust the temperature up and cook a little longer for them to crisp up. I'll see how this new air fryer handles it. And I realize I didn’t answer the why part of your question. The more expensive ones give you more versatility. Like I can use my InstaPot for stews and steaming. I’m using the Emeril right now for those tots I mentioned, and I’m pleasantly surprised that they’re browning up very nicely too. I might eventually try the rotisserie, but I’m more of a dark meat leg, thigh, and wings gal. I’ll probably still with the grill for that.
I bought the Emeril Lagasse 24 combo air fryer toaster oven combo with French doors and it's fabulous! I have baked pies in it and air fried food and baked pizza and you can even cook rotisserie chicken in it! It comes with the rotisserie pieces. It's amazing and I love it!
I have the original Emeril Lagasse power air fryer 360, which is actually just a really nice convection toaster oven and a rotisserie. I‘ve been using it almost daily for years and it still works like a charm. Takes up more space than a conventional air fryer but its also great for a lot of things that a regular air fryer isn’t. They’re almost $200 new though I see. I got mine lightly used at a yard sale for $50. The rotisserie works really well. I’ll regularly roast a big turkey breast or marinated pork loin and it works beautifully. I use it as a warmer cabinet for food waiting to be plated, and dinnerware and coffee mugs. It even makes a decent food dehydrator. I like to make croutons or breadcrumbs with leftover bread in there. And of course, it makes a great air fryer too lol.
Ninja
Foodi Dual Zone Series
Dual zones for smart cooking, but baskets are small.

COSORI
Turbo Blaze 9-in-1 6QT
Quiet, easy to clean, but lacks a viewing window.

Ninja
Foodi Air Fry Oven Series
Flips up to save space, but shallow and air fries poorly.

Breville
Smart Oven Air Fryer Series
Oven replacement; spacious, but air frying and cleaning divide users.

Typhur
Dome
Self-cleaning and quiet, but expensive with shallow interior.

Ranked #1
Ninja - Crispi Pro 6-in-1 Countertop Glass Air Fryer

Ranked #1
Breville - Smart Oven Air Fryer Series

Ranked #1
COSORI - Turbo Blaze 9-in-1 6QT

Ranked #1
Ninja - Crispi Pro 6-in-1 Countertop Glass Air Fryer

Ranked #1
Ninja - Foodi Air Fry Oven Series