The clasico was kind of a tipping point to me. Up until then it was very even, but now Real can raise the pressure weekend after weekend. That's tough in La Liga as you know that the likelihood for the two top teams to give away games when they have a massive streak is very low.
This is not quite the time to make judgments about the absolute best team in Europe. I would probably wait for a couple of final round Champions League games.
Apart from that how would you make a difference between Real Madrid and Manchester City at this point? How would you argue that aspect X or Y makes Real Madrid the better team? Because they haven't lost a game thus far? Well, La Liga isn't that strong and winning a clasico at home is of course possible for such a strong team. But does that make Real better than City? I hope we will find out soon and see the two meet each other in the CL games again. That would be amazing for many reasons