When laning against him I try my best to (smartly) secure a kill pre-6. As soon as he hits 6 you basically can't all-in on him with an equal amount of health/items, his ult will kill you at around 25% health with a 5 stack of bleed. Try to force him into a bad spot and call for early jungle pressure.
Conversely, I play to that strength as Darius. I play relatively passively pre-6 to avoid early jungle ganks. I focus on last hitting, keeping the minion wave at lease in a neutral place and only engaging the enemy champ if I'm 100% sure they're in a bad enough spot positionally that I will come out on top of the exchange. Once I hit 6 one of two things happen: either the opponent backs off because they know what Darius' ult can do and I start bullying my lane or they don't respect the Darius ult and they die.
Kakugo Ha Yoi Ka... Isshun Sengeki! My Fists Bleed Death
It's not so bad now in the stack HP meta (his bleed doesn't hurt you as badly when you have TONS OF HEALTH). Against tanks late game, he doesn't carry as hard as he did in S2. But yes, he was considered OP with his bleed stacks plus ult in S2.
You like it or you don't, but i hate people saying it's 'an acquired taste." That's just a cop out. - bookwormbabe29 on beer.