We went to York's new(ish) Gourmet Burger Kitchen for lunch today. It does mainly burgers, but has a very wide choice of toppings and sauces. My lamb burger was excellent but it suffered from one main problem: due to it's size and height it was impossible to pick up without modification (removing two super large pieces of tomato).
I don't see the point of burgers that you can't pick up. The whole point of a burger is that it's meat in a bun, and it's in a bun so you can pick it up and put it in your mouth, preferably without having the whole contents slide onto your plate.
If I wanted a meal that I needed a knife and fork to eat, I wouldn't order a burger. I'd have a salad or a steak or a curry or a bowl of dry muesli. Burgers are finger food. Fact.
At least give me a wet towel if I'm going to get messy fingers.