Nice write up. I'm at 650 miles (boo) and concur.
Handling is astounding for a 5400lb 'truck' and it definitely feels slower than it is.
One thing you didn't touch on is the exhaust. Do you also feel like they could have improved on this?
I'll add more after I get past break-in and can do some X5M to Z06 comparisons
Ps.. loved the leg-humper comment - made me laugh.