His late sucks, but his early is nice i think you should buy him, but you need so much skill and so much time to master him.
High skill cap champion but also high rewardable, also his late doesn't suck as all people are mentioning here, if you're skilled enough for insecing someone in lategame doesn't suck at all !
He is better in jungle , cause in early game he got nerfed , he will safe farm until late game and he will come and win the game
He can be mid, and I've seen some good midlaners with lee, but it's really hard to learn him, atleast my opinion about it.
You all say he is bad but its all depends on other members of bouth teams lets say they have mid lane who has weak early game like nid he can push her in and go dou inveid and denay enemy jungelr buffs and creps but also blue buff and if you manage to dive her a few times her late game will be dalayed quite a bit so ... its all depends of match up u cant say some champ is bad somewhere saying it blindly for exp. Lulu was first support and then koreans moved her to mid and sOAZ played her top with great succes ... who would guees that 1year ago when lulu was reveled as support!??