So looking through the thread, it seems that perhaps my group was just well equipped for Vordakai? Thinking about it a bit, I can see where a group that lacks a paladin or monk, or someone with a magical blunt weapon might struggle more. Though I do still think that his spell selection is a bit lackluster -- especially considering he's encountered on his own.
In a similar vein, I find the wizard in Drelev to be just an annoying speed bump. He won't really trouble any party at that level. In and of itself, that might not be a bad thing though if you are looking to just have an easy encounter tossed in there. Plus, its not as though he's the BBEG.
One thing that would be good to consider for the new version though is that I imagine most groups are likely to largely abandon the Hexploration by book 3 or certainly book 4. Its pretty cool early on, but rapidly becomes redundant. To that extent, perhaps come up with a few other ways for the group to earn XP (assuming the DM isn't leveling them up as needed without XP).