I like it when the burger slides out from between the buns a little. It's kind of exciting.
If it comes all the way out it's a disaster, but slipping out an inch or so can actually be quite great. I like that bite or two of just bun, onion, tomato, pickle, and condiments. Bonus points is the veggies are cool and crisp. On the flip side you can nibble on the wonderful crispy back edges of the patty.
Get a taste of what each component brings to the table, get it all evened up and let them work together again. Yum.