[shoshin23]

I agree with this. Showing results is the easiest way to influence people, especially when it comes to software devs and management.

As a manager, I'm more inclined to trust someone who's delivered results even in challenging codebases. It's human.

[indogooner]

  "trust someone who's delivered results even in challenging codebases" 

Yes but comparing a guy's productivity when he is demonstrating how difficult the environment is to make progress is poor management. He has already shown the results in previous project.