However, IMHO, the source of the beef can trump all that. I used to buy a year's worth of beef from a local farmer all at once. Even after a year in the freezer, a burger made from his grass-fed beef tasted better than one made from meat bought from the grocery the same day. When you start out with high quality meat, it takes a long time before the flavor degrades.
OTOH, "regular" store bought ground beef tastes nasty after being frozen for a few months.
As you might have inferred by now, good burgers are typically made from cuts like brisket and chuck that are tough, inexpensive, and high in flavor. Using high-end steaks for burgers is simply a waste, doubly so for well-marbled ones.
The fat percentage would not be difficult. Any good butcher would probably be happy to help you set such a comparison up. That is, if they don't warn you that it's a waste to use that T-bone on a burger first.