So weird that they hate To'oTo'o so much. I have watched a few of his games. He is not great by any means, but seriously good value in the fourth round. They are also the only source that seems to think that he is horrible as the consensus big board has him in the second round.
In my view PFF has improved a ton over the last few years with their podcasts, youtube channel and importantly, increased transparency. However, it does let you see that the people doing the grades aren't scouts, have no NFL experience, and are mostly just younger bloggers/sportswriters/radio guys who are getting into the scene with hard work and the new easy access to game film.
They have a lot of good takes on how players actually performed in college and should get credit for being early on hyping very productive college players like Sydney Brown. They don't have much to say about development potential and tend to evaluate traits based players mostly on what they hear from others. Their big board should be viewed largely as "here's how good everybody was in college."
PFF has To'oTo'o at #155 right now and it's largely because his stats weren't that great. He missed 49 tackles over the last three seasons, allowed an 89.3 passer rating when targeted in coverage with no ints or forced incompletions, and didn't get home very often on the 15% of his snaps where he was rushing the passer.
Of course what more traditional scouts like about To'oTo'o is that they think those weaknesses are correctable. He has good size, athleticism, instincts, leadership and football IQ and so if the technical issues get cleaned up then he absolutely has the potential to be a starting NFL middle linebacker. He probably will get drafted way before #155 by a team that thinks they can correct some of the fundamentals.