MVP wise I'd have to give it Steph. Stats wise they're close but Steph is doing it a lot more efficiently, averaging 1 less turnover a game while averaging an extra assist a game over Harden in 4 less minutes a game while leading a team that's just running through the league. Not only that but seems Steph steps it up in big games while passing the ball around more and letting others get theirs in their blowouts. Not mad for anybody that considers Harden MVP for real cause he's killing this year too but for me I got Steph at this point.
I can't find the stats either but from what I remember Steph by far had the biggest differential in on court off court net ratings.