Is Udoh really that much of an upgrade over Joel Anthony?
Both undersized centers. PF type bodies. Both players are really poor rebounders (amongst weakest in league at their positions) and very limited offensive players (again, near bottom of league in their positions). Similar defensive skill-sets based around shot-blocking, quickness and mobility. Both players can be overwhelmed physically by bigger players.
Whatever gains that are there, if any, are minimal.
I don't think Udoh is worth pursuing. Too similar to Joel Anthony.