Lets be honest, the Heldrake is pretty much an auto-include for CSMs...I wish they weren't, but if you don't want to go down the zombie-cultist route, Turkeys and Obliterators are your best choice. I have a Heldrake model (here) and whilst they are ok, they don't really fit with the aesthetic of my Iron Warrior army - so I've been eying up a Hell Blade/Talon counts-as for a while now.
The model was relatively easy to put together - with the wings just needing a bit of the hairdryer treatment to get them straight and aligned.
I had already planned on making the model as dynamic as possible - with the Hell Blade swooping low over the battlefield, so I actually started work on the base first.
Hope you like!