Simpson isn't nearly as bad as some on here make him out to be. He's a defender who can defend and if his goal line clearances were goals at the other end he'd be given much more slack. Just like Ryan Taylor does, yet he’s a defender who can’t defend but can get the odd goal.
Thirded, I wouldn't be sad to see Simpson upgraded but he's been an OK performer for us and part of the best back four we've had in ages.