As a long time BMW guy, I can tell you those wagons are really nice - but a little cramped (I'm 6'6") which is why I opted for that 2006 X5 when opportunity knocked - it checks all the same boxes (3.0 inline 6, XDrive, 6spd true-three-pedal manual tranny, BMW handling, ride & luxury, etc) but interestingly the biggest problem with the 3's (wimpy cooling systems) isn't a problem in the X5. I still liked my M3 much better though

(in the M3, after multiple failed cooling system components, I finally installed an all aluminum radiator, a high flow thermostat with an aluminum cover, underdrive pulley and a Stewart high flow water pump, and only a 50/50 mix of distilled water and BMW coolant - that did the trick even with daily romps to 120).
I'm still on the hunt for what I consider the best unicorn - a 2011-15 Caddy CTSv wagon with the recaros, panoramic sunroof and 6 spd stick. It will come, eventually!!