It was an amazing time to stay in Christian's flat. Christian is very friendly and very helpful when I needed anything.
I can only recommend his apartment because the location was really good, quite apartment, service after my arrive was impressive (water, coffee, food, shampoo, soap, cleansers...). There was everything. Only little minus what it could be, is that the flat is in third floor and there are very sharp and narrow stairs and not elevator, so for people with problems with knees, legs, could be more difficult to get up, but for me it wasn't any problem because I'm still young and fresh. :-)
If I will have chance to come back one day to Barcelona for longer term as I was now, I would again choose Christian's apartment. I can only say big thanks to Christian.