This thread is about enjoyment not difficulty. The difficulty usually ties in to the enjoyment anyways, so what the heck. But yeah, Dragon Isles is definitely the hardest directional vicious, though Namtar comes REALLY close. I think Demonic Library and Naga City are the two Vicious dungeons that shouldn't be tweaked. They are still much harder than Hard levels, but now that hard has been nerfed, vicious should be too. Something like taking the resistances off the first two forms of Namtar, or lowering those form's attack to reasonable amounts (90-105, and then 112-120). As for dragon isles, they need to weaken the guards and elites a little bit, and add "player friendly" enemies, while removing some of the harsher offenders (AA's, Goo Blobs?). And perhaps less walls in both. Of course, I'm for a full removal of VHoS, and large changes to Gaan-Telet.
We made an expansion and it is awesome. Really, you should check it out, especially if you're looking for some extra challenge.
Download over at ddmod.weebly.com!