Who are you starting this week? They are playing each other in Pittsburgh. I'm going Ben. Rivers is playing better, and Pittsburgh has the weaker defense, but Ben is just throwing the ball so damn much this season and he's playing at home.
Going with Ben too for the reason you stated. He also just has a higher ceiling than Rivers, and relatively the same floor. Seems like Rivers' caps out at around 25ish (6 pt TD league) most weeks. I like Ben's upside weekly given their passing attack.
One more from you guys...need two of:
Joe Mixon vs. DEN
Matt Breida @ SEA
Chris Carson vs. SF
Gus Edwards @ ATL