For me and I don't think this will go down well with some but I don't think he is good enough for the Championship. I've seen 2 or 3 players equally as good at defending even at this level. To play at that level you don't just need to know how to defend, distribution and pace are also needed.
Shaun, as good as he is is, way too slow. Whenever we've played anyone with a pacey forward this has been show up, for example away at Stalybridge Phil Marsh time and again got behind our defence just by using pace. The likes of Bellamy would have a field day I'm afraid. Distribution is also questionable, most times Shaun tend to get rid first, nothing wrong with that but more will be expected IF he went to Derby.
Myself I think he's a decent solid defender who could make a living at Conf Nat/League 2 but not any higher due to reasons highlighted above.