How big is the 21-quart cavity in practice?

It is larger than a typical 6-slice toaster oven, roughly enough for a small whole chicken, a 9-by-13 baking pan or two racks of toast. Measure your counter depth first: the unit is about 14 inches deep and needs clearance behind for the cord and vents.

Does the air-fry mode replace a dedicated air fryer?

It crisps frozen fries, wings and leftovers well in small batches, but a basket air fryer heats faster and browns more evenly. The oven wins on capacity and on doing toast and baking in the same box.

Expect the oven, a wire rack and a baking pan, which is the usual bundle for this class. Check the included accessories before buying if you need an air-fry basket or a broil pan.

Is it worth it over a plain toaster oven?

If you would otherwise buy both a toaster oven and an air fryer, the 6-in-1 saves counter space and covers both jobs. If you mainly make toast, a simpler oven does that for less.

How do I keep bakes even?

Rotate the pan halfway through and use the middle rack position. The oven runs hotter near the top elements, so lower the set temperature slightly for long bakes.