I have not ridden the route, although I hope to ride part of it next summer. However, I have driven much of it many times, when I lived in New York. I told the folks at ACA that the climb from Keene to Lake Placid, if you are going counter-clockwise on the loop, (Map Panel 6) is going to be a BEAR. (It would be a wonderful glide downhill though, the other way!) It is scenic (even beautiful) but it is an arduous climb, 13 miles uphill, on a very narrow, heavily traveled road. There are only three main ways into Placid, and Hwy 73 is the busiest, most direct route coming from the Northway, and ultimately Albany and NYC. Taking 9N to Wilmington would eliminate much of the climb, if I remember right, but it would also eliminate Lake Placid unless you double back.
I keep hoping someone will ride the entire loop and either post up here or have an article published in Adventure Cyclist. That would give us all a better idea about the joys and rigors of the route.