We stayed at Lemon for 3 nights and thoroughly enjoyed our trip. In a great location as everything is very local, with a metro station that reaches Park Guell also very close.
The staff were very friendly and make contact before our stay which allowed us to check in early.
Upon departure the staff also kept our bags for the afternoon (can keep them up until 18:00 which is when reception shuts) meaning we could enjoy the city one last time before we left.
One thing was that the rooms do get quite warm if you have an internal facing room, this is because there is no air flow from the outside and the A/C is pretty ineffective.
Other than that, terrific stay, and would stay again.