A few years ago I made the Alaska trip on a '91 R100GSPD. My friend was on a K1200LT with a Hannigan sidecar. He was suppose to have a GS but said at the last minute he got an offer he couldn't refuse. I was very skeptical. However, he didn't have a problem except for losing his front fender and breaking an exhaust weld, both minor problems which were fixed on the way home. I also broke a windshield brace. In fact, he did better than I when stuck in wheel ruts following "Follow Me" maintenance vehicles. Motorcycles were placed at the front followed by cars, trucks, a big motorhome, etc. behind the "follow me" vehicle. When big dirt/gravel haulers were coming at us the follow me truck would signal all to more out of the way. Imagine trying to get a 2-wheeler out of a 1' wheel rut . I had to find a place to sort of S turn out. The KLT just plowed right on out. We washed out bikes whenever we could at car wash places when back. If we didn't, the stuff we picked up from the crap on the roads would harden like a thick coating of snot. A lot more work to clean.
Was it worth it. You bet. I'll be back.