My friend and stayed in the flat last week and had a great time. It's in the heart of trendy Gracia neighbourhood on a quiet street within walking distance to major attractions and just around the corner from two beautiful squares where you can have a coffee and watch the world goes by.
The flat was very clean with all the basic furniture. Louis is very responsive and was very accommodating - he let us keep the bags in the flat post check out time so we didn't have to carry them around before heading to the airport.
I would recommend this flat for anyone who is looking for accommodation in a quaint Barcelona neighbourhood.