We had a great time at Tal's place! We thought it was fantasic value for the price we paid. It's not fancy, is a 'local apartment' in a good location with all the basic amenities you need andwe think it would be hard to beat.
The location is great, Gracia was perfect for us as we didn't want to be inside 'touristy' Barcelona (but still wanted access to good restaurants / bars) and there were multiple subway lines within easy walks. Check in was easy, and there was plenty of space for the four of us (the kids loved the bunk beds and the small selection of toys they had for them).
The temparature wasn't too bad in June so the single a/c unit in the master bedroom was sufficient. The kitchen is 'light' (fine for breakfasts and simple suppers, but not really for more involved cooking) so we didn't cook as much as we typically do but there are plenty of local restaurant and market options, including a particularly good restaurant just across the street.
The communication was great and they were very flexible when we had flight issues coming over - both check in and check out were very straightforward. We'd definitely come back if we were in Barcelona again!