I also think we'd be foolish to lose him, all in all he's had a good season, but you're right that he's been inconsistent. Next season we should see great things from him, and I expect him to be performing at the highest level then. The one thing we'll really have going for our team next season is consistency; the team won't have changed too dramatically, and neither will the backstage staff - when was the last time that happened?!
So yes, he's had a few bad games, but no, I really don't think we should get rid of him; he's been getting better and better, and when he's good he's brilliant. He's also just turned 26, which is about the age defenders start really filling their roles. Let's see how he gets on next year before making any hasty decisions.