Perhaps another angle we can take is how much you'd be willing to pay Amir Johnson. For a guy making $6M per year, all is fine and dandy because you can ignore some of his shortcomings because he's such a bargain. However, if his agent thinks his client is a top 15 PF, then he'd demand a competitive salary. He'd be asking for around what Bargnani is earning, which is around $11M next year. That's nearly double of what Amir is making and not something I'd be willing to pay.
He seems like a good hustle player that you'd want to keep around, but the question is how much do you pay for a guy that based on this thread so far, you're not sure whether or not he should be a starter. $11M seems like too much.
That's a great approach. I actually think a good comparison could be made between Johnson and Humphries in Brooklyn - great hustle, great rebounders, will put up some points without being real offensive threats, use their fouls and make you work for everything. When making around the MLE they are great values. However, I worry that the same fate awaits Johnson if he were to get a pay raise similar to what Hump got... and look at how fans/experts/etc.. have all turned on him!