If you don't mind some some street noise during the day (and at night too) in exchange for being in the actual center of it all, then you definitely need to stay at Arturo's. The place is fantastic, everything is new and clean, cloud-like beds, strong wifi, lovely guards at the door. Be it towards downtown or Coyoacán and such, no matter where you are headed, Uber or taxi only take 30 mins max.
I would never stay anywhere else. Thanks, Arturo!