Between towns, you can move pretty good. I usually go 55 in a 50. Its the small towns where the speed limit drops from 50 to 30 that you have to watch out for, cause the cops will get you, no matter what color your plate is. I have been busted on US 4 EB just east of Rutland going 55 in a 40 or 45, which was about 1/4 mile away from the start of the 50mph zone. From there, climbing up and over Sherburne Pass and down to West Bridgewater, I can see a higher speed limit of 55. East of there into Woodstock, the road isn't that straight or wide.
The new "speed limit ahead" signs are great - the yellow diamonds with an up arrow and the new speed limit have replaced the vague "Reduced Speed Ahead" black on white signs. When you see the yellow diamonds, you know to slow down.