So I've played the game once and I went on Iorveth's path. I'm planning on running it on dark mode once to prepare a save for The Witcher 3. Which path is harder on the dark mode because I want to finish this pretty quick and move on to TW3.

I did play Witcher 2 a 2nd time on insane mode (for a Steam achievement). Because in my first playthrough I choosed Roche's path I choosed Iorveth this time. (I want to see both sides). It was challenging but doable. I can't say if the other path would have been easier but as I said it was doable. Because on dark mode you can die anyway I would recommend to you to choose the path you haven't played yet. But you should keep in minde that you already know what happend on Iorveth's path and it will be faster to do the same again.

Right, I guess I'll play Roche's after all.

It's definitely worth seeing both paths before moving on to The Witcher 3, so I think you made the right choice. For the record, I think Iorveth's path is considered easier because there's more experience available. But there's probably not too much of a difference.

If you care a lot about the decisions you make and which ones get imported into The Witcher 3, then that could affect which path you choose. But hopefully you still have your save from your first run if you decide you like those choices better.

Well when I played Dark Mode I went on Iorveth's path, but I had a lot of fun with a magic build. I mostly tried it because I'd already tried swords on my first playthrough. I only took a few sword skills, most notably the one that increases the dodge-roll distance (although I only used one point in it), and otherwise focused on the magic skills. Upgraded signs are quite powerful, but I still used them in combination with swords.

Sounds like many players like to power up their Quen sign and then fight for a while, but I preferred to be more offensive with Aard and Igni and sword strikes. It was a lot of fun.

I don't know if Roche's path is better for a magic build or not. But if you haven't tried that yet and want to give it a go, I can confirm that it's a lot of fun.

I also don't think either path is easier than the other. In Iorweth there a event when you loose one of your swords, so if you are going with 'uniqe' sets for Dark Mode, then it might actually kill you (it took me a moment to realise what killed me :D ). Other than that? No.
I think in both paths you can get powerful gear to fight, and in previous Witcher elves gived more magic oriented items and I think it's similar here, but I'm not 100% sure.
Good luck. :)

guess I'll go a magic build. Gotta make another run in hard mode or something to try a mutagen/alchemy build xD

Yeah that confused me too. Fortunately the sword just gets "unequipped" but it's still in Geralt's inventory, so once I figured it out I just had to equip it again and everything was OK. Still, clearly an issue from before Dark Mode was added, when having a full set didn't matter.

Yeah. It's just a bit of annoyence and if you remember about set weakness it's nothing at all. But I died 2-3 tiems because of this. :D

Roche is harder, because if you do Iorveth, at siege, you max Geralt out, before chapter 2 even ends. Also all those harpies in Vergen can give you quick and easy money and materials for the dark armor set. Those necrophages on Roche and the Golem can be a real handful, early on...