I think the draft network is doing their own work for sure, but it is not in any way tied to the feelings around the league. They create their own grades based off of their own work. That being said, it isn't so different from what PFF does. Their rankings are based more off of their own rankings than what scouts and teams around the league feel about prospects. Andrew Thomas was a top OT and top 10 player until Daniel Jeremiah released his first Mock Draft which had Thomas in the mid to bottom of the first round. Now the site has adjusted their rankings to put Thomas at the 18th ranked prospect and 3rd ranked tackle.
Personally, I feel like it reduces their credibility to the level of individuals on this board who watch a bunch of college football. That doesn't mean it doesn't contain some good info, but it does mean they are still one of the last places I do to determine where a player may go on draft day and where a player ranks among his peers.
I don't think they moved Thomas because of Jeremiah.
It's more likely because they are still watching tape on guys and adjusting rankings as they go. They have 5 or 6 guys there so overall rankings will adjust as people catch up on tape. Although there is an element of group think across the industry.
One of the reasons I like TDN is because their overall big board is an amalgamation of their individual big boards so you are getting a broader spectrum of opinion which is more likely to be accurate.