As a Veigar main, I think this is a slight buff for him. It may not feel like it, but it is. Well at least in my opinion. He has more range now so he can farm safely or snipe someone from afar. Even though they gave a huge change to him stun, it is still useful. It's just hard to land. I never use my stun during laning phase, unless my jungler is delivering a gank or roaming to another lane. It also stopped dashes when the opponent touched the sides of the event horizon when it fully popped up. I never use my stun in lane because I know i'm never going to land it and it cost so much mana. Speaking of mana, his passive got buffed. His passive is way more useful now. 1.5% may sound small, but it's more than 1%. It really helps a lot in lane because you can stack with your Q more often now! What I do is just farm in lane, and poke down your opponent mid laner with your Q. :)
He's a straight up counter to LeBlanc, one of the most used mid laner and a champ that fits in the meta right now! His stun can stop her dash mid-way, better late game (Instant Primordal Burst one-shot!) , and has the Q range to farm to stay out of her W range!
He's still good! Just really difficult to play now! He takes ton of practice now! c: