There are both pro/cons of the startup ecosystem in Boston.
-- Its harder to raise funding in Boston compared to SV. In addition, a big part of the funding discussion is timeline to revenues, which is just completely ignored at this stage in the valley.
-- Given this higher bar, the startups that do rise in the Boston ecosystem are of generally higher quality. I was at the launch conference last week, and several companies in the demo pit were honestly just "me-too" class projects. GreenGoose (at Launch) was an example of a Boston startup.
-- Nonethless for consumer web/mobile, Boston startups tend to be inferior to the valley ones. The reasons for this are multifold. (a) The angel/adviser community seems less comfortable funding companies that don't have a clear path to revenues. (b) The entrepreneurs themselves are not the best at designing products / UX etc. (c) The better Boston consumer web/mobile companies move west anyways
-- Given the less "bubble" ness in Boston, hiring top-notch engineers from MIT, Harvard, Olin or other good technical schools is a real option for startups. I'm hearing horror stories on the west coast+ NYC of companies that are funded and can't find the right engineers.