I play Tyranids right now, but I am thinking that for my next army I want to use Cadians with a few grey knight squads thrown in. Is anyone using a similar army? I guess my biggest question is, would I be better off with plain old Marines. My thoughts are that perhaps i should get both and use the GK when I face CC armies such as nids and use plain old Marines when I want to play shoot em up...against Tau or Necrons. Thoughts?