I'm not sure that Brown is improving. I think the defense is making Brown's play look better. It's easier to intercept underthrown passes or break to intercept one when the line is getting pressure that forces the ball out quickly.
I'm not sure what is going on with Haden in Pittsburgh, but a lot of the time, good and bad seasons for corners are tied to how the rest of the defense is playing. If the pressure isn't good in particular, then the corners are in trouble no matter how good they are.
I know what Haden has accomplished in his career is much better than anything we've gotten from Brown. Plus, I know that that starting corner spot could use an upgrade, so I hope Dallas is looking at that and not just thinking it drafted players at the position in the second and third rounds, so that's good enough.
If they don't view Haden as an upgrade, I can live with that. Not even looking into the possibility of upgrading is the type of thing this front office is liable to do to leave us lacking.