I have never rode my bike on the Alaska hwy, but I've driven it, there and back again. It is one of the most beautiful hwy's I've been on in some parts of it, but it was brutal. There were many long sections where the whole hwy was ripped out, to be repaved, and the gravel road that was left was full of large rocks and big ruts, usually. Some construction zones went for 10 miles or more.
There were also many really bad sections, of rough pavement. Really rough pavement. That permafrost is not kind to roads.
I went in June though. Maybe later in summer, the construction is mostly done.
Between Ft. Nelson and Watson Lake blew me away, it was so pretty. Lots of wildlife. Even wild horses were all over the rode. It was snowing in late June in the passes though.