The gap between them isn't exorbitantly huge or anything but I still believe Madara's superior for now. Madara taught him a list of decent jutsu (probably where he got that Uchiha shield for the Gedo from) but not everything. I think Obito understands his capabilities too. Just look at his response at Madara breaking Edo Tensei, "Very much like you to do that." There's probably a different translation for it but I'm sure it's along those lines. Obito showed his great skills with Madara's war fan, but Madara was the one who used it to reflect a Bijuu level attack from Naruto.
Both have their own set of tools which makes them a threat, so they're bound to be better at different things (Kamui can do things Madara probably wouldn't be able to accomplish). I give Madara an advantage because of his obvious array of jutsu knowledge and overall skills.
