I like what I've heard of the rules, but I just can't see myself ever picking up these particular models. The Skitarii line looked great! All spindly, vaguely insectoid, and just alien enough. The cult mechanicus stuff just isn't quite there for me personally.
Electro Priests: I remember seeing one or two of these guys in short stories, and they were awesome! The models are just... constipated-looking blind shirtless guys with sticks that look awkward to swing. I think a different weapon (maybe a spear/glaive?) would have helped these guys out a lot. They're also yet another set of imperial heads that are just sort of... lumpy.
The kastelans are actually pretty cool from the rear and in profile, but the front is just sort of goofy. It makes me think of Buzz Lightyear or a diving suit or a certain animated robot in red armor.
The kataphron have lots of cool details to them, but I dislike their overall appearance for the same reason I disliked the Lord of Skulls. Tankotaurs are just goofy. Any given piece of them works seperately, but together, I just go :\ Maybe if they'd just done a miniature tank with an armored servo skull instead of the goofy torso-having servitor? WHy do you need your tank to have a vulnerable torso and spinal column exactly?
I like the data smith though. He's cool.
Not to rag on anyone else's enjoyment of the models mind you. I know plenty of people don't like my pointy-headed eldar much.