Dark Eldar are argueably one of the best model ranges from Games Workshop. They are stunning, and when done put together well are an amazing army to see on the table. Being a Dark Eldar fan from the start (when the book first came out), I am prepared to go full board to adding to my already 7000pt + army of the Dark Kin. However............
Rules, rules, rules, and rules.
Personally I think the Mandrake model is one of the best out there. It just digs into my time traveller memories of images seen long ago for the Morlocks in "the Time Machine". I love the models, hate the rules. So what did that translate to...... No new Mandrake models in my collection.
The same goes for any of my armies, but for my dark eldar it is more prevalent. Once I have a codex in hand and the rules are known, I will figure out any new models that need to be purchased. Even the Voidraven will be on hold until I know for certain what they will have and be able to do.
A pretty model sitting in a box, or a cabinet.......... is just taking space.