In my opinion, it is too early to judge that Barcelona is better than Real Madrid in this season. There are still some good match ahead for both teams. Actually Real Madrid is suffering specially in defense line. They're recovering from it and I hope they'll try to secure the top position of table again by beating Barcelona.
In the league, Barcelona has always been the better team but for overall performance, Barcelona will always be second to Real Madrid. Real Madrid mightn't be playing well but they'll still end the season with a good season as they'll win some trophies Barcelona can go trophy less this season. Barcelona has scored more goals than Real Madrid by a big margin meaning Barcelona attackers are doing more of a good job than all the stars packed at Real Madrid. Atlético Madrid are currently top of the table but that'll change after the game that Barcelona is currently playing as I think they'll win and go back to the top of the table and they have the goal difference to stay top.