We rode a section of the GWT from north of Flagstaff down to just north of Jerome last week. It was a great ride. The portion north of I-40 was mainly wide gravel roads. Things got a little more primitive and fun south of I-40. The only slightly difficult spot was coming down the mountain into the Verde River valley. The trip down and up the valley was spectacular. We chose to go into Jerome rather than turn west and stay on the GWT.
Our original plan was to go around the mountain at Flagstaff and pick up the GWT farther north, but the road we started on was closed due to Fire Recovery.
The trail was well-marked with carsonite signes with the round GWT logo.
We had planned to get on a dirt road south out of Jerome and go over to Camp Verde, but the road was closed.
I managed to attach the gpx file of the GWT portion of the ride.
This was part of a week long mostly dirt loop from Albuquerque to the GWT and back.
I posted the full route on both GpxXChange (West, "Great Western Trail Info") and on DualSportMaps ("New Mexico Arizona Great Western Trail")
The green line is the GWT. Red lines are part of the ride getting there and out. Cyan line is our intended track.