I purchased a 2011 Expedition EL Limited with Load Leveling, moonroof/retractable running boards and NAV along with the rear Headrest DVD system. So except for the coloring and the better leather it is just like what you are contemplating. I purchased my truck back in the end of June and put on nearly 1000 miles in the first two weeks so it would be broken in for towing. Since then I went on several family outings towing our 20'ft bowrider weighing about 3500 lbs. It towed well mainly because of the 6 speed transmission with the tow/haul mode.
My biggest gripe is the leather seats (which the King Ranch takes care of, I wished I like the color combo on the King Ranch). In my Limited they seem somewhat thin and the driver side cushion seems under stuffed and I am getting wrinkling and creases in the leather which eventually will crack. I haven't pursued this with the dealership but I think I should. So good thing you are looking at the KR.
I have not had many problems with my truck except that the factory remote start didn't work lilke a normal remote start and would stop the engine when the key was placed in the key receptacle requiring the truck to be restarted. Dealershiip couldn't/wouldn't reprogram to operate as most systems do. So I found instructions on how to do it and did it myself in less than 10min.
Also the Factory Ordered (apparently dealer installed) Headrest DVD's are not integrated with the Touch screen NAV so the sound if played though the truck speakers needs to be tuned into an FM band which is not very clear all the time.
I recently had the gas gauge fail on me. It was at about 1/2 tank when I parked it on my relatively steep driveway one night about a week ago. The next morning I drove the truck and it was telling me I had 25 miles left in the tank. I suspected somebody syphoned gas from me as my added trip computer said I should have 20 gal left. When I went to fill up sure enough it took 20.1 gal. So it was a sticking tank indicator that was fault. It broke free when filling it and I haven't retested on my driveway yet as I am waiting for the gauge to drop to about 20 gal again.
Other than that there have been complaints on these '07+ Expy's having shifting troubles. There is a lot of activity on this forum with people having all sorts of troubles (mostly software related I suspect). I haven't seen anybody with an '11 or '12 with this issue so I'm not sure it has been designed out or just not old enough.
Another common issue seems to deal with paint quality. Again there are several threads on this issue also. The paint does seem a bit on the thin side and I got the optional Tri-Color Metallic White at an additional $475 so you would think it would be better but it really doesn't seem so. I again have no issures but it is practically brand new. It may very possibly be a sign of the times with the types of paints used today or a cost savings thinning of the paint, but it is what it is.
If you will tow with your Expedition I would suggest an aftermarket gauge so you can keep an eye on the engine and transmission temperature. The engine temperature as the one in the truck seems to just heat up to a specific point and just stays there. Even if the digital readout shows it is heating up a bit, the analog instrument gauge doesn't move a bit. It is controlled by the computer I suspect. The truck doesn't have a transmission temp gauge so that is nice to have. I use the Scangauge II and recommend it.
As of now I have 4500 miles so I really don't daily drive it.
Also if you ever want to modify your truck with a lift, you may want to know that there are limited options with the '07+ style and none when you have the Load Leveling option as far as I know.
Good luck with your new purchase.
Johnny