Tried to get it right about 4 times before, but failed. Wanted to give these successful tips to help others.
Seasoning first - blended chopped onion with season salt, kosher salt, garlic powder, and black pepper. Mixed it up with lean ground beef and made up some 1/2 to 1/3 lb patties.
Set-up - large BGE with the stainless rack on the fire ring. Nothing fancy.
The cook - fired up the BGE and ran it up to about 650 degrees. Opened the lid and added the patties. Kept the lid open to get a good sear on each side. Removed the patties from the egg and put them in a foil covered pan. Closed the egg and brought the temp down to about 375. Put the patties back on, closed the lid, and cooked them for 5 minutes on each side.
Checked the temp with my thermopen and they were a perfect 160. Removed from fire and placed them back in the foil covered pan. Let them rest for 5 minutes.
These dudes were awesome.