Now a lot of us love Oga, including me. But I honestly think he owns a little bit "too" much.
And to be honest, I'm sure Oga will probably win his fight against Takamiya, flying him 7 and a half circuits around Earth. Even if it seems bleak for Oga.
But honestly, and I'm probably in the minority on this, I really would rather have Takamiya beat Oga. Using pure logic, Oga is going against someone who's had more experience than him. And this isn't a matter of standing on a certain pedestal that ignores experience anymore (Ex. Oga and Nasu).
Takamiya has the freaking Lucifer on his side. So any way you see it, Takamiya should win.
Oga has won too much, and whenever he loses (which was like, what, once or twice?), it doesn't feel "genuine." If Takamiya beats Oga in a fair fight, I think that would be a little relieving, proving Oga is still a human being and that he could still be legitimately challenged in the future of Beelzebub.
And seeing as how Takamiya hasn't used any of his specific spells against Oga yet, I really hope he pulls a "Now I'll use a real spell" and overwhelm Oga. But of course, knowing Oga, he'll find some kind of way to overpower that.
Obviously: Oga wins
Logically: Takamiya wins
Nasu wasn't the guy to do that, but Takamiya is on a comparable and potentially better level than Oga.