I've never tried one of those convection combos, but I do highly recommend an airfryer with 2 baskets. It does depend on what you're cooking, but I've used air fryers with one big basket, and air fryers with 2 smaller ones, and I definitely prefer the smaller 2 basket ones

If you're cooking bigger things frequently, then the large one might work out for the best, but the largest things I regularly cook are chicken schnitzels (my butcher does massive heart shaped ones), and chicken Kievs. I prefer to cook those either in the oven or fry them in oil anyway, so it doesn't bother me

I usually use the air fryer for lunchy type things like chicken tenders, chips, or hash browns. Sometimes sausages. But I can fit about 4 large tenders or 6 sausages per basket, so it works out just fine for me