As I suspected, the Gangplank nerfs accomplished next to nothing
Sure, I suppose it may have made a few fotm spammers drop him but he's still ridiculously powerful and what makes him a problem has yet to be addressed. These problems are:
- Hyper scaling champion with a safe and in many match-ups, dominate lane phase
Mana cost nerfs accomplished nothing here. He rushes
, some even start
for mana return and
exists. mana isn't a problem.
- Hyper scaling champion with global pressure
This needed to go a long time ago. You could give his ult a 5 minute cooldown and it wouldn't matter. All he needs to do is ult bot once (hell anywhere where there's a fight) and he's made an enormous difference, even if no kills are granted. And because he can rush 
and/or
, often times he can use it again within 162-144 seconds rather than the 180. Sure 2 1/2 minutes but that's pretty ridiculous for a champion of his scaling. The cooldown doesn't matter, his ult needs to be semi global at early levels so if he wants to use it outside of his lane, it needs to be a fight close by.
- he still gets bonus gold from his Qs passive and he's one of the best power farming champions in the game. Seriously, between this and his ult and bandit applying melee benefits on his Q, he is still impossible to shut down. Even if you go even, by level 9 he will have somewhere between a 1k-1.5k gold lead, and if he builds
, which his lane phase is safe enough for him to do, he can add more to that just by going even. That's practically a 3-5 kill lead that he can make go away - how is that fair? How is that fair on a champion that that scales as hard as he does? You fucking butchered Nasus for doing this at the end of season 3 and he had to farm in melee range. And he couldn't bully lanes from the start either.
All in total, the problem with gangplank is that he's impossible to shut down but you can't simply suffice for going even with him either, because you're never actually even. You basically have to win the game by 25 minutes or gangplank AoEs your team to death. And he can do all of this while simply electing not to interact and farm with his Q/Barrells and almost no champion can shut this down.
You continue to refuse to nerf what his actual problems are. And his problems are game breaking issues that leave his enemies with almost no real chances of doing anything about it. You can continue to make him harder to play by nerfing mana costs, cooldowns and all the like but that won't change anything until you nerf those so hard that we are back to where we were with pre rework GP, the worst champion in the game. And it's because you won't change the incredibly unhealthy, overpowering and unfair elements of his gameplay that shouldn't exist on a champion that scales as hard as he does.
If it were not for yasuos bug, gangplank would still be the best performing top laner in the game despite all the nerfs. And that's pretty hilarious.
Tl;dr
Gangplank is still broken (winrate doesn't matter, it's about the choices you have when playing against him and you have no meaningful choices)
-make his level 1/2 ult semi global -remove his bonus gold passive on Q and he still preserves the "pirate plunder" identity with his silver serpents. -make his Q trigger ranged effects so Grasp and Bandit aren't granted melee rewards for an ability that is clearly ranged. -begin looking at reverting some of his other nerfs because these changes would make him a much healthier champion who gives you actual options when fighting against him.

to increase the slow again.
And maybe something else, because litterally everyone just leaves that one for last
cough. Although i feel like i should state that i have had minimal difficulty with dealing with his trades in lane but that may be due to my experience with him shrug.
disagrees.
with
in the few times i do go toplane. i run vamp runes and masteries and laugh as he tries to poke me away with every Q healing me for 50health(shorter cd then his oranges and way less mana) at lvl 1.
main I've found that all-ining GP with ghost flash has become quite a bit more lethal to him since he dies 40 HP faster as the 40 HP nerf clearly puts him at a stat-check disadvantage with me.