These should be useful for my Eberron campaign, in which the heroes will soon be ivestigating some Dal Quor-related deaths. One thing bothers me, though: why does the Insomnious gain bonus HD from the Dreamheld ability, rather than the more common and more easy to adjucate +5 HP? Because it doesn't really rely on attacks, skills, or feats, the only thing that makes the HD boost better than temp. HP is a bonus to turn resistence, but considering that it's 3 HD behind its CR already, that won't make very much difference.
Well, basically was going for increase in HD because many powers are more difficult to affect it at that point. And, as you mentioned, its harder to turn that way. Also a save increase isn't bad.

Could still go for HP though, will think on it.

PS: IMHO, you should stick with Belly Button Lint with ATTITUDE as your screen name.
I've just been changing it all day ;)