Yes, it is MUCH easier to farm with Veigar's Q, but...
That stun delay is killing it almost totally. HOWEVER, it can work if you make the cage smaller. If you are set on the delay and making it more of a trapping cage as opposed to a super op stun, then you need to actually make it a cage, NOT a mobile arena where they can still totally dodge stuff. Also that nerf to his ult is pretty damn noticeable. I'll keep trying it, and maybe I just suck, but he's going to need more love if you guys want this direction for him. I honestly do like the Q though.