For as overloaded as his kit is, Ekko is actually ok with me
I'll set one thing straight first - I've never played Ekko myself, so take what I'm saying with a grain of salt. I've seen plenty of Ekko's carry games and go ridiculous 19/2 scores, or something, but it's nothing I haven't seen Zed/Talon/LeBlanc, or any other assassin do. I actually smile a bit when the enemy picks Ekko, because I actually find him really fun to fight against - it actually feels like a fair matchup. Now compare this to laning against something like Heimer, Chogath, or Ryze - THOSE I feel are frustrating, unfun, and all that. Either they have so much sustain or safety in lane, or they become so ungodly tanky that it's completely pointless to fight them once they reach the point of no return.
Now I'm a main AP MID, so it's rare I see an Ekko on my team, so usually I'm facing them in mid when I do see one. I used to be afraid of him because of what I read on the forums, so I would play extremely defensively against him until I learned how to read what he's going to do.
I do not find him difficult to beat; he's actually one of the easier matchups for me. I even play Evelynn mid, and can win lane against him rather easily - and with him being underfed, he tends to fall behind later in game and doesn't really pick up. His skillshots are slow and predictable, and his stun requires him to get dangerously close, while you stand in his field for him to pull it off.
I've faced him quite a few times, and no matter what champ I'm playing, I've never felt like he is oppressive, and I've never felt frustrated when he does kill me, because it's him exploiting a big mistake I made, rather than him just being blatantly overpowering. I haven't really seen him tweaked a huge amount since release, when I saw topic after topic complaining about him, but maybe I'm wrong and he's a lot different now than he was on release.
I wouldn't complain if a teammate picked him, because he certainly does have carry potential, as any assassin should, I honestly think he's one of the best releases in recent history. Then again, I haven't seen a Tank Ekko yet, so I might change my tone when that comes around.