Some people have said that to me, but I've had far more comments saying that people were pleased not to see Sam's faults magically written of as well so it might be a point of view thing.
All I can say is:
1) The early parts of this fic were written during the beginning of season 6, so while it's AU, that was the Sam most heavily influencing me at the time.
2) I'm not someone who ignores all of the times that Sam has walked out on his brother, shot him or who pretends that Sam's Heaven was anything other than, as Dean pointed out, completely free of Dean (and John).
3) Now that I'm this far into the fic I'm comfortable saying that, just like in season 6, there's more going on than meets the eye. If that something will be enough for you in the end or not I can't say.
What I can say is that past the initial 20 or so chapters the fic gets more heavily into non-Sam stuff and that is where the Destiel area comes more heavily into play and dealing with preventing the Apocalypse from restarting and Lucifer conquering all. I just needed to deal with the fact that Sam had abandoned Dean at Lisa's for a year before Dean could move on to the other stuff.
In the end it's your call. All I can say is that I've got people who have been following from the beginning and that was well over a year ago now.
Other characters include: Michael, Raphael, Bobby, Samuel Campbell. To a much lesser extent: Crowley, Roy, Walt, Becky, Meg, Chuck...