Blitzcrank I think is a bit too specific an example to make, because his knockup is exceptionally cheap, and tends to feel bad because it mostly only serves as a follow-up to his Q, which is itself strong enough to not need more hard CC further down the line. Other than that, I'd say Gragas's E knockup + stun feels pretty cheap in some circumstances, but otherwise I'm finding it difficult to find displacement in League whose duration feels excessive relative to its cost, downtime or counterplay.
What I would like to see, however, is less CC in the game overall, and I think one way to achieve this could be to remove the nudge-type displacements that have been inserted on a whole bunch of abilities, namely Kled's ult, Quinn's E, Sejuani's Q, Vi's Q and soon Ornn's on-hit effect against Brittle targets. They're basically mini-stuns that serve to interrupt channeling and dashes without locking champions down much further, but they usually end up feeling more annoying than anything else, and don't feel especially strong for the actual power that they hold. If the intent is to actually displace enemies or disable them, then they could have their knockback or duration extended, but otherwise having a fraction of a second's worth of a knockup in a game that is already saturated with crowd control is really not worth it.
