Butler measured 6037 (6'4") and 280 before the draft last season. That 280 was significantly down from his college playing weight, and he's now listed at a pseudo-official 300 on the roster at patriots.com.
To me, he seems more suited for a 3-tech/4-tech role (3-4 DE type) in the NFL, with situational use as a 1-tech. However, due to the lack of healthy bodies for the interior DL last year, Butler ended up playing a crap-tonne of 1-tech (with Brown trying to play NT/0-tech), as did Guy (also better-suited for a 3-tech/4-tech role, IMHO).