I've been at Petra's apartement for two weeks, I was traveling on my own but I can assure that's perfect for a couple... the flat isn't right in the center of the city but very very close...in 10-15 minutes you can reach every point of interest by bus or tram, at your choice... the Zizkov district is reeeally nice, full of non-touristic restaurants and pubs, and on the other side of the hill you can truly find some Neukölln vibes... the flat is absolutely lovely, well furnished,comfy and, despite it's located on the 1st floor on a big street, it's absolutely silent,quiet and offers all the privacy and relax that you need at the end of a touring day... I higly reccomend it!!!