a slight buff to his ratios wont really fix the reason why people are complaining about him.
if possible, do something about his Q mechanic. Like have it shoot through minions like galios' gust and allowing the player to select who to Q2, kinda like urgot's Q.
That or make the Q animation way faster. Anyone experienced in lane can dodge his Q so easily that he has no lane potential.
even if his Q is fixed though, his team fights/survivability is still terrible. Unless you do something like increase his base shield (W) numbers, or AoE (E) range.
Someone mentioned, Lee sin is fun to play, but it feels like he's fun doing nothing. Thats basically how he is right now. He has no presence in a team fight unless super farmed, which doesnt really ever happen unless the other team are complete feeders.