I haven't been up that way in some time. It has been at least a year so YMMV. In Boston I had great service, South of Boston (New Bedford, Fall River) area I had great service, Mattapoisette was a little spotty but acceptable (didn't go much further down the cape) and down to Providence area was also great.
I've never had a problem with sprint speed. Seems to me that its more of an on off thing. Areas of good service give consistent good service and areas with poor service are poor. I can't reallysay I've ever had really poor service with sprint. The only downside is the frequency they use doesn't penetrate buildings as well as at&t's 850 but really that is a toss up because some buildings i couldn't get service with my iphone I get with my hero and vice versa.
I can't speak to 4G service, but I get splendid 3G everywhere I travel in MA. One notable exception is the Rt. 202 corridor from Amherst to Rt 2, where its very spotty. But once on Rt. 2, good service all the way to Boston.
