09.01.2013 @ 16:39
Roche is fighting to preserve Foltest's legacy, and/or Temeria. Unfortunately, the side effect of this is that Temeria will remain a realm where non-humans (including mages, though arguably they have it coming) will be brutally persecuted on a daily basis. However, Roche's path will ensure a relatively strong Temeria is around to oppose Nilfgaard.
Iorveth is fighting to create a new, independant kingdom where both humans and non-humans are welcome. Granted, he's probably responsible for more atrocities than Roche (especially if he's meant to represent both Isengrim and Iorveth from the books), but the Pontar Valley will be the first de-segregated kingdom and, if all goes according to plan, will also be a strong bulwark against Nilfgaard. Unfortunately, siding with Iorveth means Temeria will no longer exist and probably weakens the Temerian, Redanian, and Kaedweni fronts against Nilfgaard to boot. However, Iorveth (Isenveth? Iorvengrim?) and the dwarves of Vergen beneath Queen Saskia will attract a lot of Scoia'tel to the cause, especially since Dol Blathanna didn't really work out too well for non-humans. So they may be able to break the Nilfgaardian army from the rear with commando strikes while Henselt and Radovid get their act together.
Personally I tend to side with Iorveth on an instinctual level over Roche. Both have done (very) bad things in the past; neither is what you'd call a nice person, but then neither is Geralt when you get right down to it. For me the tipping point is that Iorveth has changed (as noted by several NPCs throughout the game) and is fighting for change; whilst his past may be bleak at least he is trying to do something positive with his present. Roche, whether he intends it or not (and since he leads the Blue Stripes I'd be more inclined to believe the former than the latter) is fighting to preserve a system that casually brutalises people. To me the choice comes down to what the better potential outcome will be; a united Temeria might be a safer bet, but I figure that if you're going to be dragged into a political whirlwind you may as well go big or go home, and trying for a free Pontar Valley is definitely going big.