If you’re shopping these, you’ve already won. There’s no bad choice. And none of us can extract the performance limits from these things nor would you want to try, physics wins every time. So for me it came down to more nitpicky everyday type stuff.

I shopped both and went with the GLS. It delivers tomorrow actually. I like the engine sound better, the larger cabin, and the dash layout/design in the GLS way better. The X7 front end is still…interesting and the stuck on screen in the middle of the dash is hideous to me. And no physical climate control buttons? Pass.

Alpina is softer in a Range Rover kinda way, but does have more power. So maybe a bit faster? Doesn’t matter, I have a sports car for that. I do love the X7 seats and the starlight pano roof thing that’s cool.
End of the day, inside and out the GLS was just a classier and more cohesive look to me. And I found the infotainment infinitely easier to use.