The O-line he had were 2-3rd stringers after the first. What impresses me about Rivers is is pocket presence. He also does not rush throws and is not scared to pull the ball down and take a sack or throw it away. The pass or shovel pass or whatever you want to call it with Sproles shows you what kind of vision he has. He also does not panic in the pocket, looks off receivers etc...
There's no way to call him a bust this early! Im a Brees fan but in my opion, Rivers will be a very special QB, whether it be with teh Bolts or a different team.
Another aspect that I am impressed with Rivers is his quick release. It showed over and over again how he can hit the slants, comebackers, etc... Time will prove what kind of QB Rivers is, but to those that call him a bust hasnt really seen the kid play. IMHO- "vision" and pocket presence is some of the most important traits a QB must have.