There are few websites on the internet who are as polarizing as Pro Football Focus (PFF). Not that the writing is poor, or the takes are awful, but it is based around their grading system. There is a lot of confusion surrounding their grading, and many fans find them to be too far fetched and almost made up.
Either way, with the bad, there is some good. PFF does put in a ton of analysis to their work, and are very thorough with many of their analytical articles...not their grades.
Recently, PFF put out an article with a list of players who are entering their third year in the league, who could have big seasons.