TomTom IQ Routes, Boston Area

I've has a Garmin iQue for several years, but it's approaching end of
life (no battery life when unplugged, built-in antenna failed,
frequent crashes and memory dumps).

I commute from Sharon, MA (south of Boston) to North Reading (north of
Boston) 4-5 times a week. I'm interested in the traffic features of
some of the new GPS units and/or software out there but I'm looking
for some reviews that are not just repeats of press releases. Can
anyone who lives in the Boston area with one of these devices tell me
how well, or poorly, the traffic features work in this area? I'm
especially interested in how well it re-routes based on traffic
slowdowns.