I've rented an apartment in Paris for a week - last October. And in 2004 we rented a house in the South of France to catch a stage of the Tour. Can't help you with a name since it wasn't Barcelona. But both experiences were PHENOMENAL. I am sure we saved on money by doing a lot of eating at home. Plus, we really felt like we were at home, rather than temporarily somewhere, if that makes sense.

I'm jealous, can't wait to hear about your wonderful trip!