Both of you guys are wrong. Kled is weak early game. I would know because I am Kled.
No tho, his early game is terrible. I don't even think he has a winning match up (Early game). Maybe against Teemo. I don't even know if I would say he becomes good mid game either, but he is an amazing late game champion tho if he can build lots of HP with one good life steal item, and be tanky.
I don't see how he can be a lane bully early game cause almost any champion who goes top lane can dismount him in one full rotation by level 3, most of them can dismount him at level 1 for example an x3 Riven Q.
Also, he's got a lot of counterplay. You can avoid his ultimate, even counter it with certain champions. You can abuse him if he is dismounted and dive him all day with a jungler. Especially if it's a jungle Kled, have fun farming him cause he won't be on his mount.
So yeah, he is not strong in all phases besides late game, but even then he has a lot of counterplay. His biggest issue is he needs buffed, not nerfed. He needs to gain courage far more faster when dismounted cause you have to pretty much last hit minions to get some courage which is crap compared to hitting a champion, or turret which gives the most. Also, jungle camps should give him courage, not just for last hits (in which jungle camps, don't give courage at all really. If they can give him that buff, he would be an awesome jungler, and that would probably be his best role then, but for now it's top.