Joss Whedon's run on Astonishing X-men is a perfect example of long term plots paying off in the end. He replenished the X-men series and put his trademark charm on it. The humour, drama, love and loss Joss Whedon is so great at are all thrown into the mix. As well as crazy plot twists and exploring the grey are of black and white. Joss sure enjoys writing Kitty Pryde, who he has quite an affinity for. He gives her the most important role she ever has had in "Unstoppable". Joss' Astonishing X-men run doesn't have any other Marvel big events affecting it, so you need not worry if you didn't read Civil War at the time. "Unstoppable" is a gamechanging arc. It takes some gutsy plot twists you wouldn't expect. The purpose for the ressurection of Colossus is revealed. And ONE X-men will be given a beautiful send off as a heroic sacrifice.
"Unstoppable" ends on a high note. The reflective last scene really brings it all home. It feels like a screenplay of a movie that is quite possibly the most beautiful scene in any X-men comic.