He seems to be in a weird spot. He doesn't see competitive play, he stomps low elo, but suffers a lot in high elo. If I remember correctly, Heisendong (Masters/Challenger Heimer) stopped playing Heimer because Heimer was too weak in the meta. Surprised he wasn't part of the mage update. :(
His turrets are paper and gets one shotted easily at all stages of the game...
i was too surprised at him not being at least low-scope for the update.
i would give his turrets ward-like hp (scaling with level, only hit-able with autoattack) 2-2-2-3-3 or something like that, or making the turret's hp scale harder into the lategame.
or making him able to pick up his turrets to reduce its charge cooldown.
his issue is that even when ahead, he becomes almost irrelevant lategame, while he pays in midgame by not being able to roam, and early when he is not able to leash because he has to set up turrets (that last thing could be solved by giving him more initial max charges)
I feel bad for Heimer. He's one of the few champs that gets hard countered painfully compared to other champs in certain match-ups. If you buff him too much, he becomes oppressive in low play but if you nerf him, he becomes irrelevant around plat. I don't follow Heisendong but I believe he's picking him up again after mage patch to see where he stands now. Was really hoping he'd get some attention.
one problem is that he is counter picked to easy
oh look is that a heimerdinger? play gangplank. rush sheen. one shot his turrets with Q EVERY SINGLE TIME. free 6 gold and serpents and now he has to waste mana replacing that turret every . . . 4 . . . seconds.
Would be hilarious if they made his turrets health like vision ward health. Lol
If the enemy is really focusing on destroying Heimer turrets, he has the option of maxing rockets instead. Players against Heimer often become too focused on destroying his turrets, so then he can punish them whenever they go in to attack them. Even with maxing turrets, place them in such a way that it becomes awkward for the enemy to get in range, which gives you more freedom to punish them when they do.
i hope 100 nerfs, and a permanent complete rework
Hes actually really fun top lane with windspeakers + banner of command + zzzrot. I ran it alot pre portal nerf and it was braindeadly simple winning lane. Most of the champs that can kill your turrets cant deal with the empowered minion from banner of command. That coupled with all your health regen from your passive + windspeakers makes harass basically meaningless against you (and you can even heal your turrets decently). Its alot like how singed would feel if he shot his poison in front of him. You struggle after mid game, but there are plenty of match ups that flat out cannot deal with that build and so you force the enemy team to concede objectives or 2/3 man you, which opens objectives elsewhere. Youre sort of forced to push all game over and over, but unlike proxy singed, you dont have to die to get the farm or the tower damage.
That said, there are matchups that you cant really deal with, especially with this build, either.
Suffer in high elo?....... but then again I dont know how NA side fares but in EU side he is a monster.
I kill people in high Elo with Heimer and even survive 3 man ganks. Granted i didnt do it lately because i am supporting :( here's hoping sometime the Que will get my secondary role and put me top.
Only thing I would give is Heimerdinger's Turrets to have the same range as ADC do and give them some resistance with 200 extra HP. That and let them auto-upgrade themselves, if you didnt notice his turrets deal the same dmg at all stages no matter how much you leveled his Q or how high lvl Heimer is, you need to reapply them in order for the turrets to deal bigger dmg and get more HP.
Maybe they should bring the stacking Magic Resistance Shred his Turrets had back.
With 
i push top lane like mad and i shred all tanky champs.
Altought i sometimes swap with 
because the turrets apply Rylai's Slow.
That said, he really needs an update :( i was really surprised to see him ignored in the mage update.
For me the most important thing is that he now has way too much similarity with Zyra. Heimer was the original counterengage champion, who would set up his zone and punish divers extremely hard. With the mage update they aimed for Zyra to become the main counterengage champion (with a very similar style of setting up a zone of "minions" and defend that zone), but it means that Heimer is now basically a weaker version of her.
The main problem with Heimer atm is he's not tanky relative to all the amount of damage that's going round which really hurts his early/mid game; that sounds odd but let me explain - Heimer has to be able to live long enough to bait enemies into attacking him so that his turrets can do the work and kill the enemy, if he gets one shot by a huge amount of burst he cannot do that and the enemy can just walk away. The addition of damage masteries means there's much more "free damage" floating around for everyone this season than last season and there's much more of a tendency for poor Heimy to just fall over before his turrets can do anything.
Idk, I play a lot of melee assassins and he can be really annoying. I remember the first time I played against the donger I was talon and I had no idea how to play against him. He had pushed a tower before backing once.
He needs to be able to buy upgrades for his turrets at the itemshop
Upgrades like Increased tankyness Extra range Making the lasers ground/cripple people Possibly other mechanics like a damage ramp up per shot on the same target or shredding of resistances.
hell they could even put something like this in a viktor style unique item. with possible upgrades for his other weapons aswell.
and a final upgrade to one of his 3 ultimates, like the H-28Q Apex Tank where instead of a large turret its a tank for heimer to drive in for a while boosting his resistances and giving a shield with the turrets health value after x seconds or if shield is depleted it stops
this would allow heimer to drive his turret around and attack people with it himself
or Hextech Rocketship where he can sly around in a big rocket shooting the smaller ones for the duration and having a lot of movespeed
well you get the idea
like 3 smaller upgrades for turrets and a big one for one of his abilities
I liked where Heimer was at the end of season 5, but season 6 has not been kind to him. Even if he dominates early/mid game he falls off so hard late game that he is completely useless minus some team fight ulted grenades. His cooldowns are so high that you get punished severely whenever you miss one of his abilities. Couple that with the mobility creep and the insane amount of AP he needs to raise the health of his turrets and deal a decent amount of damage.
Furthermore I have been playing the new zyra as support and she is just so much better than heimer is right now. Free pop up turrets that don't die instantly and crazy low cooldowns. Plus her snare and ult are much easier to land than heimers
The problem is that against melee he usually destroys but against tank melees, he does NO DAMAGE. In mid lane which is comprised of mages, they just wave clear his turrets, he gets ganked easily ESEPCIALLY IF THE JUNGLER IS SMART. He can just smite big turrets or small turrets and finish Heimer. He is just useless....
