The hakpaks can be opened with NWN's hakpak viewer/extractor. Only one hak is encrypted. (Nothing big though, all the good stuff is accessible).
I bought it because I wanted to support DLA first and foremost. I have gotten many, MANY tips and good help from them making NWN Custom content, and all the hard stuff like skin meshes.
They kick ass.
Secondly, I bought it for the stellar custom content. The Mist Dragon is .... animated Artwork.