Do ratings matter?

[GlennN]

Hoping you folks can give me some feedback on how much ratings matter. For a dynasty/franchise mode to work, there has to be an actual difference between players based on ratings. So, for those who have played around with this enough to say, do you notice a difference in how ratings impact the play?

Like for example:
In OL/DL matchups, do you notice better DLs getting penetration?
For QBs, do you notice more accuracy consistent with the ratings?
For RBs,do you feel a difference between backs quick and slow backs?
CB/WR interactions - do WRs seem to get open when ratings suggest they should?

Lastly, please note whether you actually control the players or use coach or spectate modes.

Thanks much!