air fryers are convection ovens.
a heating element with a fan to circulate the air.
There is nothing wrong with the egg shaped ones, but if you look at table top traditional convection ovens like the Cuisinart, you may find you have more options to cook different types of food.
My mother has both kinds and she uses both of them regularly. For smaller items like a couple of chicken thighs she uses the egg shaped one similar to the PowerXL model. For larger items like a whole chicken or pork roast she uses the Cuisinart.
