Ok peeps. So I don't think you're right in saying that Tobi was scared of Madara. I think,he was surprised that Kabuto had done so much homework and even came into possession of Madara's body. Also, Tobi has been using the name Madara to incite fear into people and start this war,so it might been an issue for him if Kabuto showed everyone that Tobi wasn't Madara.
I think Tobi would win atm as his space time ninjutsu would be able to avoid all Madara's big fancy attacks and Madara hasn't shown any ability with this same technique.
I also know that as Tobi harnesses the 6 biju, he has a very strong attack force with possible 6 tailed beast bombs,V2 Biju and full Biju mode with all 6.
Not to mention the powers of both Rinnegan and Sharingan at the same time, which is possibly the most powerful set of eyes about, although he hasn't shown MS,which means he may not be of Uchiha blood(far as I know he hasn't).
Still to the victor go the spoils and I think it's Tobi.