This can't be stated enough, and has been pointed out by a few others in this thread already.
Taking a player with his skill set, and adding him to a D-Line with K. Williams and Dareus, is already leaps and bounds better than the D-Line he was playing on with the Texans.
All 3 players, along with our other DE (whomever that ends up being) will benefit greatly by him coming to our team.
We as a fan base should be focusing on the WHOLE defensive line's improvement, not just what Mario will be doing by himself. He won't have to do it by himself, he's just another piece that takes pressure off of everyone else around him. You can't double every D-lineman on our team, someone's going to get through on almost every single passing play.
Offenses should be put on alert; "Prepare your anus" would be appropriate here.