I rode a KLR from Prudoe bay to Anchorage. About 1200 miles, far more than half of it unpaved and have to say they are capable bikes that are pretty much bullet-proof. There were 2 KTMs with us, both had issues. 4 BMW GS' - two 650s and two 1200s, they were reliable although the 1200s were too much bike in the mud.
If I were to have only one bike a GS1200 may be it. They are comfortable, have enough power, handle really well and have enough suspension for unpaved roads.
Not the prettiest though...