I travel Rt 20 from Syracuse, NY West to Buffalo and east to Albany. It is a good route nicely bypassing most major metros till you hit Albany area.
Cannot help you on the rte 20 issue in Massachusetts as my favorite route through Mass is Route 2. But some sections of that route have steep grades and hairpin turns. So without knowing what you are driving I cannot advise. I can say I have no hesitation driving it in my 27 foot MH