Eso is definitely nice, and a big boston sports fan. There was an old 7l and Eso t-shirt that had reggie lewis on it and read "reggie lewis is watching". Unfortunately it has been sold out forever.
As for him being the only good rapper in Boston, there are definitely more. . .
check out Reks, Termanology, Project Move, and Megaphone (Moe Pope and Headnodic)
Im definitely someone who misses hearing good hip hop and has an ipod loaded with 90's tracks but recently has been impressed with a couple good non-local albums:
Blueprint 3
Only Built 4 Cuban Links 2
Kid Cudi's new album
the new Slaughterhouse album
All good stuff, Slaughterhouse and Cuban links 2 are like taking a time machine back to the golden era. Blueprint 3 and Cudi are just good music, well produced, different than the norm for crap hip hop thats been on the radio for the past 5-10 years+.