We are a family with a 10 year old and 7 year old. We have just returned from a super 10 night stay in Manels apartment. There are many great things about the apartment and for our family the size was fantastic and top of the list. The lift also came in handy after a long day sightseeing. The location is superb and so much can be seen within walking distance and the underground is very close by. El Ravel is a fantastic area to spend time in, less touristy with the markets and bakeries close by and great places to eat. We always felt safe. Manel was very welcoming and informed us of everything we needed to know.
Two top tips...if you are staying on a weekend you will definitely need earplugs, this is not a reflection on the apartment but of Barcelona in general and if you want to go to a Fc Barcelona game, 4 days before match the returns go on sale (keep an eye on their website) and you can get tickets from the club shop on universitat, a 10 minutes walk away at 10 am. Finally we loved Manels apartment and it helped us to fall in love with the city.