Yep, 400 hours in F:NV is nothing really when you consider that there are four different endings, and to get the endings does require at least a chunk of the game being played differently. Oh, and don't forget all the mods that can be installed and used - there are some pretty good quest mods to get.
800 hours in PS:T is easy (for me) - I loved the game so much I replayed it multiple times. Oh, and there were differences if you played it by talking to everyone vs fighting everyone (less xp going combat route, but quests ended differently in some cases, and gave access to different rewards). You could also get access to different factions depending on how you played the game. You could also get endings where TNO would find out his real name (which you never find out). There were also mods that could be installed. Not to mention doing different playthroughs for the different love interest's... and that you can play the game differently whether your a thief, warrior or mage.
Edit - oh, and every time I played through I did EVERY quest I could. Even though I'd already done them, I just can't rush through a game I like & enjoy.
Not sure what I expect to get our of Original Sin, but I really hope that there is easily 100+ hours from it. I did put a lot of time into the previous Divinity games, and from the updates and everything I've seen it should hopefully be possible to get a lot of hours into the game and it should hopefully have good replayability. But we'll see.
Last edited by Kamatsu; 04/09/13 08:24 AM.