I personally like stuff like Zed's ult and Fizz's ult. Both are very obviously their strong damage part. You can outplay it, they can outplay with it. It is delayed, giving your said time to outplay it, and it doesn't really throw them into the middle of a fight (Zed's does, but most don't just run in and ult the minute a teamfight starts unless it's to dodge something).
Leblanc's is sorta forced in my opinion, especially since it doesn't get shorter with CDR or anything. Yeah, it was completely BS how before Leblanc would literally W, Q, E, and then pop back to CSing while you now have 50% hp. Plus the fact she has a delay on being able to reapply her passive now just means she's essentially a poke mage, not an assassin. If her passive didn't have a target cooldown, Leblanc could use W to gap close, land E which popped her passive, QRQ to pop passive again and she would be able to actually burst people with the delay still being present. Or you could change it so that after she's hits 6 and she procs the passive, her abilities do an extra bit of damage during the cooldown period. That way there is a delay to allow you to outplay, and then burst if you don't.
Also her passive delay isn't lowered in gamemodes like URF, which seems really unfair considering everyone can spam but your spam literally has a forced delay.
It's also completely unfair that an ADC gets 3 crits in a row and you instantly die even if you have armor. With Lux at least she had to hit a slow moving skillshot first. Caitlyn I feel depends, because you had to be pretty close to be hit by said net but eating a trap you literally can't see (hidden behind teammate, under dead bodies, randomly invisible, etc) I'll agree is bullshit though.