Thoughts about Poacher's Knife
Thinking about the Smitems, it occurred to me that a big difference between Poacher's Knife and the other ones is that it doesn't really enable the gameplay that it incentives; mostly, it just rewards you for pulling it off. Ranger's enables you to hard farm with the AOE smite, stun, and health/mana restoration. Stalker's and Skirmisher's enable ganks or other fighting with damage to champions and either a slow or damage reduction. Poacher's mostly just rewards you for managing to counter-jungle with a little bonus gold, a burst of movement speed, and a reduced cooldown. (Sure, the movement speed does enable you to get away afterwards, and the cooldown reduction might enable longer stays in the enemy jungle, but these aren't really that effective at winning battles over jungle camps.)
So, here's my idea: Make Poacher's-empowered Smite deal bonus true damage to monsters in the enemy jungle. This would allow you to take advantage of Poacher's to win Smite wars over buffs and such. Another idea would be to give Poacher's an AOE like Ranger's (but without the stun or health/mana). I'm honestly still not sure how much I like Poacher's in general, but I think that some sort of change that causes Poacher's to make you a substantially better counterjungler is what's necessary.