Marcia's place is really nice, and just as the photos depict. The staff at the building were wonderful, accommodating, and very very helpful (especially Victor!). The apartment is big enough to comfortably lounge in after a long day seeing the sites. It's very centrally-located in Centro, which means it's very conducive to transport, though those for whom noise is a concern should be aware that this is one of the busier areas. Also, our trip was the middle to the end of May, meaning that we had to deal with heat and mosquitos; though neither of these were too big of an issue with fans and open windows.
Marcia was a very responsive and hospitable host, as well. We had a couple of problems with the Internet while we were there, though she was very quick to address everything!