For my trip last summer from CA to AK I went with the K60s F/R. No regrets, very good in gravel, OK in mud and decent on pavement. Like you I didn't want to change tires during the trip. I have 8000 miles on the K60s and they will go another 3-4K. I'll probably go back to Tourances as my normal riding leans more to street with a little gravel.