I downloaded this mod for the first time a few weeks ago. I was skeptical; one of the major virtues of the IWD game was the ability to create my own part of adventurers. But of course their endless silence gets a bit tedious at times...but the overall fell and story of the game is still very good.
But after trying it for a while (I'm in the Temple of the Forgotten God right now) I must say I'm quite impressed. The NPC are powerful and useful, without being ridiculous. So they are the type of characters I might bring along myself. A little short in the arcane department perhaps, but I remedied that by making my protagonist a 1/2E F/M. The dialog is also quite good and I really like how their background ties into the game; Nella has been very interesting so far in terms of her ties to Kuldahar. Selven and Teri seems to have the most dialog thus far, with Korin coming along nicely.
Looking forward to the rest of the mod.
Note: Playing it with Item Upgrade, IWD UB, IWD Tweaks (not everything installed), IWD NPC, and finally some of my own tweaks on top.