Hi David - I have an 06/56 reg Sorento XE manual, purchased new, but pre registered, in April this year. Since then I have toured Portugal, Spain, France and Southern Ireland. Fuel consumption has been 25/26 towing 1400kg, and 30 - 36 solo depending on conditions (but I am not a heavy footed driver. Towing is very relaxed and has less effect on the car than normal saloon/ estate cars. My most satisfying drive with the caravan in tow has been over the Envalira pass in Andorra (over 8000 feet) which the Sorento took in its stride.
I do not particularly notice the extra fuel consumption compared to my previous Ford Mondeo diesel because the tank is much bigger - ie the range is similar but it costs more to fill up. ....but so far most of my fill ups have been abroad where the fuel costs less.
Regarding 4wd I have been a bit disappointed to find out after buying the car that you can only use it in very slippery conditions - snow and mud - otherwise you put a strain on the transmission and tyres. ....so I have had little or no chance to use it so far. Normally only the rear wheels are driven - but if you want permanent 4wd you need the XS model.
Overall I am very pleased with the car, which I think is excellent value for money.
Hope this helps
KeithJ