They're different kinds of players I'd say. Kondogbia was injured for a large chunk of the season, so Imbula probably had the better season overall. They're different players though, Kondogbia is a monster defensively, that is his strong point, winning back balls, while Imbula is a lot better offensively and technique wise, he's actually a good dribbler and has a strong shot on him.
As someone whose watched a lot of Kondogbia, I'm quite surprised about the hype he gets to be honest. He is a very good tackler and interceptor of the ball in midfield, but he isn't a superstar by any stretch of the imagination, he wasn't even Monaco's best midfielder last season. Joao Moutinho was their best midfielder, followed by Toulalan IMO.