Ingrid is a fantastic host and the apartment is just what you're looking for if you want to be in the thick of things without the street sellers and pick pockets of La Rambla (which you can still walk to in 15 minutes). Close access to the metro and a block from the fancy main street. It's very very very centrally located in an upper class neighborhood that we felt very safe in at all hours. There is a bar in the basement of the building (it's several floors down so literally no noise from it) that is fantastic for a glass of wine or gin cocktail. It's comfy and weird and we met so many fun people there.
I really can't suggest this place enough. We travel quite a bit on Airbnb and this is top 5 for sure.