I have a player who is currently rog1/sor(dragon)2 who asked which prestige class would be more useful for playing this AP. I told him it depends on which style he wanted, subtle/stealthy or not subtle/forthright. That didn't satisfy him. So in your opinions which prestige class works best in Shattered Star, Arcane Trickster or Dragon Disciple?
Does the character want to mainly be a blaster that gains some tricks to deal with traps at a distance? Arcane trickster is best, especially if the character learns vanish, spells that cause opponents to be blinded (or even various fog spells while wearing fogcutter lenses or a goz mask), and/or has a high initiative (to cast while opponents are still flat-footed); sneak attack applies to ranged touch spells like acid splash, ray of frost, Reach shocking grasp, etc.
Does the character want to be more in the thick of combat and act as a skirmisher/flanker? Dragon disciple is best, especially if the character learns self-buffing spells; adding a couple extra levels of rogue (or, even better, one level in snakebite striker brawler) to bring sneak attack up to +2d6 may be worthwhile.
I told him it depends on which style he wanted, but that didn't satisfy him.