This isn't the be-all, end-all, but:
Collins has played 1,109 snaps and missed 387 snaps in the regular season since the 2015 opener. There was virtually no difference in the opposing quarterbacks' Total QBR scores when Collins was on the field (53.8) compared with when he was off it (54.6). The Patriots' opponents actually fared better with Collins on the field across a range of categories: yards per play, yards per rush, yards per pass attempt and third-down conversion rate.