Agree, my biggest wish was also a 740Ldxdrive. This does not exisist and so the 50Ld just spare 2-3 Liter but cost as a Year-old Car at least 10 Grands more. So the feeling of Driving the Diesel ist not a good one (for me), Decision was easy to made.
I tested every Kombination of Motor and Drive (the 50LDX 4 times). the 760Li ist nearly perfect, but massive expansive in Austria and sadly also without the fourwheel. But i want to have this in the Mountains right here...
Conclusion: 740L D Xdrive would be the perfect 7 Series
Until this ist not available, i´ll drive my 750L i Xdrive...