I posted this on another thread, but it's more relevant here:
I have 2,400 km on the clock now, since we took our first long road trip in the KL about 10 days ago - Edmonton down to the border and back again to complete our permanent residency application, about a 1200 km roundtrip.
The 'kee (V6 North w/towing package) behaved very nicely - quiet, smooth, comfortable to the extent that when we pulled up in Coutts 6 hours after we set off, neither of us were at all stiff or sore.
We got about 9.6 l/100km cruising at about 120 km/hr on the way down, mostly in 8th and occasionally 9th on some downhill sections. That crept up to 10.5 l/100km on the way home but we had a bit of a headwind that day (and I did do a quick 'high speed test' on a clear straight section - she goes past 160 km/hr with ease, didn't like to push it any harder than that!).
I did notice on the way back the transmission seemed to hold 7th a lot when it might have been in 8th, I found accelerating a little bit and then letting the car settle back down to the cruise control speed would often make it shift up.