Hi, I'm a platinum toplane main, and I've been playing alot of poppy.
I've toplaned, jungled, supported, midlaned, I've played full tank, AD off-tank, support tank, armor pen assassin, crit carry and settled on my preferred build
"the Buckler Build" http://www.mobafire.com/league-of-legends/build/poppy-top-the-buckler-build-446871
Poppy has a few qualities I deem too strong, and a few qualities I deem too weak.
First of all, Poppy's early damage is WAAAAAY too high at the moment. Her E stun into passive-aa reset and Q and tiamat cancel into aa, one shots anyone not building hp or armor after longsword and tiamat. This makes her super snowbally, as a longsword start into a rushed tiamat is a won lane.
Now for her weaknesses.
Due to not having resist shred/penetration in her kit, or any meaningful magic damage. She's prone to easily getting itemized against. Despite her max health damage, she doesn't stand a chance vs the likes of Nasus, Shen or Mundo after their first back. As they will outdamage her with cloth armor and bami's cinder alone.
Her passive, while good during laning, and a monstrous ability if itemized for. Serves little to no purpose for tank Poppy. Where other tanks or juggernauts have sustain or damage reduction for prolonged teamfights, Poppy does not have that luxury late game. The cooldown is too high, and it's easier for the enemy to deny her to pick up her shield than it is for her to risk getting it.
All in all, Poppy is my favorite champion at the moment due to her utility and diversity.
I do have some suggestions to improve her to a more healthier state. Take it as you will.
"Passive: Iron Ambassador - STATIC COOLDOWN: 18 / 14 / 10
Poppy periodically throws her buckler on her next basic attack, to then fall near her target, where it remains for up to 4 seconds. If the buckler kills its target, it bounces back to Poppy automatically. Enemies can step on the buckler to destroy it.
The buckler grants bonus range and 30 - 200 (based on level) bonus magic damage. When Poppy picks up the buckler, she shields herself for 15% maximum health for 4 / 5 / 6 seconds and it's cooldown is reduced by 4 / 5 / 6.
Shield will be refreshed, not stacked if already shielded. Iron Ambassador resets Poppy's autoattack timer."
Now, this does not count when you kill a unit. I know, this over a 100% shield up time late game. Do note, that in order to get it, you have to run past the angry tanks, bruisers and carries before they destroy it to enjoy it's benefits, and you'll be out of position to peel for carries too. For someone without any sustain in her kit, this will give tank Poppy some love. A squishy buckler sniping Poppy can't risk it however, and will have to wait her 10 seconds before she can throw another passive.
"Hammer Shock - COST: 35 / 40 / 45 / 50 / 55 MANA - COOLDOWN: 9 / 8 / 7 / 6 / 5
ACTIVE: Poppy smashes the ground in front of her, dealing physical damage to all enemies hit.
INITIAL PHYSICAL DAMAGE: 40 / 70 / 100 / 130 / 160 (+ 10 / 20 / 30 / 40 / 50% AD)
The impacted ground becomes unstable, slowing enemies standing on it before erupting after 1 second, dealing the same physical damage to all enemies hit and + 15% max HP in magic damage. (capped at 250 vs monsters)
SLOW: 20 / 25 / 30 / 35 / 40%
Hammer Shock deals 80% damage against minions.
This will make Poppy far less snowbally when given an early lead, while scaling well into late game. It maintains the reward for landing a wall stun and it also punishes people lingering in the second eruption and gives her some mixed damage, but not as overbearing as, say Gnar. Buy armor and hp, don't get stunned for the magic damage. It will also help the cdr tank Poppy who likes spamming Q's, while changing little for the more aggressively built Poppy's.
The rest of her abilites are fine. Her W is a little unreliable at times, but that's just a matter of fixing/tuning/specifying. Her E does enough damage, physical damage makes sense and scaling stun duration is fair. Her ultimate is super satisfying for everyone when used right and is overall a great ability.
This concludes my thought's about Poppy. Feel free to call me out if you think I'm wrong, or my proposed changes are BS. I like praise too though, so let me know what you think.
Thanks for reading; Discuss!