I like Hang, but he is not strong at the point of attack. Urbik has the size and strength to be a significant upgrade. I also believe Urbik played center in at least one game last year (am I wrong?) The question is not cut Hang or Urbik, because Urbik is not going anywhere (and should not, in my opinion, a good pick-up with potential). The question is Hang vs. other back-up guards. Too close for me to have an opinion on who should be cut or retained.
One last point: I think the OL will be the most pleasant surprise on the team this year. They are big and have talent, but are raw and have not yet jelled. I think Chan is keeping the heat on players like Levitre and Bell by starting/playing others in their place. Sure, Bell looked real bad against Denver, but he was facing a player with speed and body lean on the rush that is somewhat unique. He did a good job overall last year at three-quarter strength. He should get better. I think Wood and Levitre are emerging as respected players. I think Urbik will be okay at guard as he refines his game and to me, Pears looked at least servicable in the preseason. I also watched Hairston's every snap the other night, replayed them even on NFL.com. I don't know when he starts, but prediction here is he is a high-quality NFL tackle for many years. They have this line moving in the right direction, and loss of Hang would not be significant, IMHO.