Is he good enough to be a backup? Probably. Is he a starter? Probably not.
He is in the same position Tebow was. If he had no baggage he would likely be on a team, but no one wants the circus in there town.
Tick, this isn't really a response to you personally, you're just the last one to weigh in on this. I've been thinking about this a lot lately, what with the Garappolo deal and all, and I respectfully push back on this even more than I did before.
Michael Vick. Ray Lewis. That Suh guy. Half of the Cincinnati Bengals. Anyone that has beaten their wife/girlfriend and then went on to be Jerry Jones' new shiny thing. The NFL has proven that they are not at all swayed by "circus". Belichick made it work with Randy Moss, Corey Dillon, and a handful of others that are, in their own way, a "circus".
If there was an NFL team that was, in their current state, not a Super Bowl team, and yet WITH Colin Kaepernick they ARE a Super Bowl team, I guarantee you he would be in their uniform. I am more and more each day convinced that that is just not the case. He's an excellent ATHLETE, he is not a good NFL QUARTERBACK. Those are not the same things, and Colin is experiencing that right now.