We just spent 4 lovely days at Cesc's place. The flat is charming, near supermarkets, bars and transport. The flat was perfectly clean and equipped. We were five and the space felt great. It might be important to mention that the 5th-6th bed space is a sofa-bed located in the living room. This, however, was perfectly comfy and given that the flat is in a small, quite lane we had good sleep.
Cesc was a great host. Good communications since the begging, always willing to help and very friendly. Make sure you go to the old part of Gracia neighbor as is beautiful (Have a drink at Bodega Marin, corner of Mila i Fontanals/Puigmarti. You'll feel real Barcelona spirit). And if going to Sagrada Familia, try to go 8 am as the amount of tourists is overwhelming (and we went in February). Overall, I would recommend stay in this little-well located-charming flat!