Not meaningless, but not incredibly useful.
Nurburgring is one of the most downforce rewarding tracks in the world. A lot of the track is around 120 mph or more in a fast car and those fast parts are filled with hill crests and long sweepers. Basically made for aero. If you look at the top road cars lap times, they all have great downforce.
For a road car, even one you bring to the track, aero wont matter nearly as much. Maybe an exception is on say highly illegal backroad excursions, but blasting down back roads at 130 mph is just not something people do much.
I think the best track benchmark we have is C&D’s lightning laps at VIR. That track is just better to compare with for real world performance than Nurburgring. Plus there are more controls in place so no marketing silliness.
I did a gen 2 cadillac ctsv event in maybe 2009 or so. It was at a track in new york. Fun event, bought a similar cts-v later.
Have done a number of hpdes and set a local lap record, so am a decent driver. The biggest issue i had is i wasnt allowed to push the car beyond 60% or so. Seemed like everyone else felt like they were near their limit though.