Attunement servitors are like little floating paintball guns. They literally fire containers of a glowing chemical that sticks to whatever it hits and makes it easier to see. In game this results in giving everything in the 4"AOE -2 DEF. That's it. Nothing fancy, just light up the enemy and make it easier for the rest of your stuff to hit. Since it's an AOE attack, they don't really need to be concerned with a direct hit since the effect happens regardless. I really like the models and they were super easy to paint, since well, there isn't a lot to them.
The Optifex Directive unit is a true support unit. They have 3 different modifications that can be done and they're all pretty useful. They can give your vectors pathfinder, if they don't already have it, give them a magical weapon, or repair them. I had a terrible time painting these guys, as they are more of a necessary unit, rather than something I just want to take.
That pretty much finishes my army for now. I have one Diffusor model to paint and then I'll have my 25 and 35 point lists finished. Looking forward to getting in a few games now.