I haven't played with the voidraven at all, but in my opinion, the razorwing is the better bet. once you buy the missiles for the voidraven, it ends up being much more expensive than the razorwing, and just isn't worth the +1 strength on the lances. I guess the mine might be nice, but it seems situational. so far my razorwing has been doing great. it's very good at killing infantry when you can unload a splinter cannon and 4 missiles into one target.