I think our best six batsmen are Cook, Root, Trott, KP, Bell, Bairstow. Only harsh on Compton if you think that a selectorial error gives him sinecure.
There was an interesting view in the Sunday Telegraph a couple of weeks ago that I actually hold with though - the ideal batting line up would be Cook, Compton, Trott, Root, Pietersen, Bairstow. We know Bell well enough but he has never quite convinced for long periods - what do we learn if he mullers New Zealand? At least this way we find out about Compton for once and for all whilst boosting Root up the order and restoring Bairstow to the spot he deserves...