I finally made it out there a few weeks ago. It's fairly punk-centric which is probably a good thing for someone with my tastes. I found some neat stuff in the used bin for very reasonable prices: The Kinks "Lola vs the Powerman," a Chris D/Divine Horseman LP, a 9353 LP, a reissue double LP of the Who's "My Generation" and "Magic Bus" and a few other things that escape me at the moment. However, being a punk-centric record store meant that they actually knew their stuff and many new/punk/hardcore/indie LPs were on display for ebay-like prices. I'm not necessarily saying they were overcharging but the stuff they had could probably be found cheaper elsewhere. Case in point, Opal's "Early Recordings" LP was going for $40. It might actually be worth that much but I have the feeling that if I sniff around long enough I may find it at a shop with a less clued in staff for a much cheaper price.
All in all it's not a bad little shop. I will likely head out there again to scour the used LP bins at some point in the future. Plus, there's a very good comic shop just a few doors down. Who knew Sommerville was such a cultural hub?