I have a regular group of folk who come round once a month to play board games - anywhere between 6 and 16. Lunch is almost always something off the BBQ.
One month, as an experiment, I cooked some burgers low and slow - on my pellet grill, but you could equally do them on any smoker. I cooked them at about 180F, for a couple of hours. They were very tasty, really juicy, and had a great smoked taste.
The following month, I was asked if I was doing the smoked burgers again. Or rather it was more like a demand.
Since then, I've always cooked them the same way for that crowd. As someone explained, it isn't that they are better, it is that they are different, and they can get grilled burgers anywhere.
You need thick burgers for this to work, with a decent fat content. What really surprised me is that leftovers reheated really well in a microwave, a couple of burgers in a covered dish with a tablespoon of water, and that was my next day's lunch.