With all respect to cordelli, there is no way that I'd take 495.

If you follow 95, you will not actually go through Boston. Instead, you'll be following the road that Mass people know as Route 128 -- it's a 6- and 8-lane beltway on which traffic flows smoothly except at rush hours (7-9, 3.30-6) or unusual conditions (accident, construction).

Rt 495, the Great Circle Route, is 10 or 12 miles longer, and the traffic density will be as great or greater than 95 in June. 495 is the primary route for those from Conn/NY/and beyond to get to NH and Maine, and it also has a far higher % of trucks than 95/128.