The trick is the balance, between meat, seasoning, vegetables and to a small degree, sauce and seasoning. E.g. putting too much meat on it and less than 3 out of 4: salad, onion, tomato, pickle, would be too little. Ingredient quality matters a lot. Cheese is a nice bonus. Variations according to taste are “obvious”, hot or mild sauce, different veggies…

It shouldn’t be uncomfortable to eat, but I’m also disappointed if it’s too small. Imo, you should need both hands.