From the trailers, it was rather obvious what the deal with the Dark Urge is and it didn't disappoint me at all. Personally I believe the Dark Urge is a better experience than regular Tav, but that depends on what you want to play.
Because, The Dark Urge playthrough gives you not only that you're
a Bhaalspawn. But also what you've been doing up until the Nautiloid. Certain classes make incredibly little sense waking up with. I wake up a Cleric of Helm, or something similar only to realise I was a Professional Dark Urger until then? That doesn't make sense to me, even less so for The Vigilant One.
So for me, if I want to play certain classes I'll go Tav.
I do agree that it's entirely silly party members being so forgiving about this. There's not even a dissaproval from say, the ever righteous Wyll after the obligatory scene. I think this is more fun if you go multiplayer and one of the group is the Dark Urge, and you're all trying to figure out who, or somesuch. Even though that too would become rather obvious after the first scene.
I don't care about 'balancing' playthroughs, each has its own merits and faults. I thought I would love going as a female Lolth-Sworn Drow and pick my Drow-Options every time it came up. Now *that* is missing out, as no one is fighting you. Even Kagha is all excited for your arrival. It was fun for a while, ordering everyone about, but rerolled post-Gobbo camp.
