I did it after doing a modified WHW route as a bail out. I was planning on heading north for another week or so but twisted my knee on a scrambling route Nr Fort William so took it as a bail out route that would allow me to see how bad my knee was without leaving my self in the middle of nowhere.
The great glen way is not technical at all, my setup was two small panniers and a rucksack on a rear rack that I would put on for rough sections (such as coming into Kinlochleven on the WHW), I did not have to put the rucksack on once for the GGW. I took the walking route and there where a few non technical single track section but all doable with the a trailer IMO. I personally found the scenery boring and repetitive I would have hated to have walked it, it was very wet though and hence misty. I left FW at 12:00 and arrived at Inverness at about 15-15:30 the next day traveling at a very slow pace with several pub stops and one pannier still full of food!
Write up and photos of GGW section here.http://www.crazyguyonabike.com/doc/page/?o=RrzKj&page_id=128419&v=2q