The stats don't lie: McGloin is actually in the middle of the BIG in passing efficiency at 144. Bolden is nearly 20 points behind the next worst BIG QB at 85. And it's worth noting that Gray and Martinez, the only challengers to RoBo in badness, at least are running QBs. Mac has 4 TDs and no picks. Bolden has 1 TD and 4 picks.
Now, I know the folks who say stars don't matter and stats are all a conspiracy will poo-poo this. But the gap is so huge and obvious that there is no way around it. McGloin is vastly superior. He probably is not a top 6 BIG QB in reality, but he would need to play a lot worse to match Bolden in the race for the cellar.
I was clamoring for Bolden to get a chance when McGloin faltered last year. He's gotten his chance, though, and has not delivered. Mac has to be the guy. 5 games with stats and the obvious difference in leadership/moxie/confidence/offensive play is enough to decide this competition.