Having traveled that route many times when I lived in Bennington, I offer this. Route 9 is a pretty ride over a VT two lane road, with lots of curves and some steep grades up and back down. Add to that that the route takes you through Bennington and getting to the Albany area to head south is over more two lane roads. My personal choice with my RV would be to take 91 south until you reach Meriden, CT, which is south of Hartford. Take 691 west to connect to 84 - you will miss the most of Hartford traffic and some of the worst part of 84.
Travel safe. (We will be at the KOA in Putney, right off of 91, tomorrow).
Neil, Lin, and our furry companions, Ashby and Cody. 06 National Surf Side.