The Opportunist were a band from Massachusetts who started out in 07 playing a heavier style of screamo. I got the chance to see one of their first shows and snagged their first demo, which I don't think a lot people have. If you download it you'll hear that heavier screamo sound. Shortly after their first demo, they got a another singer and changed to a heavier hardcore sound. Below you can listen to their second demo from their myspace page which has tracks along the lines of that. Sometime after the second demo they seemed to slip through the cracks and disappear. Too bad.
Demo CD-R (2007)
Demo II (2008)