The mods I've tried: SoS, TDD. And there is no comparison between Quest Pack and these other efforts. The writing is indistinguishable from the original content, and the content really blends seamlessly with the core game.
I played through SoA as a mage a few years ago, but never finished ToB. Now I'm going back once more through the game and thought I might try out a few mods for a fresher experience (though I've forgotten most of the original plot elements already). At first I installed SoS and TDD and was kind of disappointed that I could instantly tell what was Bioware-created and what was fan-created.
With QuestPack, it is hard to tell. Thanks SimDing for your talented writing and efforts in creating a great mod. I'm having a lot of fun with my half-orc Lawful Evil Kensai Jose.