This is the first year in the past decade the Suns have done well against the dregs. It used to be the Suns only played well when they were "up" for the game, but would play down to the level of the worst teams and lose a lot of games. The Suns still do some of that, but they have the ability to win those games almost every time.
What we don't know is how well the Suns will play with everything on the line. It's not like there is much history to work from. The only players returning from the playoff team of two years ago are:
Stoudemire
Marion
Johnson
Voskuhl
Outlaw
They have added some guys with playoff experience in Nash, Jackson, and McCarty; but Q, Barbosa, Hunter, and Shirley have none.
Typically teams without playoff experience don't fare well in the playoffs. However, those teams usually finish in the bottom tier of the playoffs, are playing much stronger teams, and aren't used to the intensity of the playoffs.
The one great thing about the Suns is that they have had a target painted on their backs for the entire season. Playing against fired up teams is not going to be a new experience.