i've stayed in Se&Bi 's apartment for 9 days and the time was pretty good! The apartment is very nice, has 2 levels, not far from the center (you're reaching Duomo walking 15-20 min) and lots of shops and cafes nearby (half way to the center). But it's not in the overcrowded center, and it's really important in Florence. The apartment is very close to the river and to piazza Michelangelo with wonderful views and great running routes! For me it was especially important - and i had everything for running near the apartment.
If we're talking about the summer - the apartment will be really good for a couple because there is one bedroom (of two) with air-conditioning, and it turns pretty important when outside so much hot like it was in July 2013 (40 C every day).
Special thanks to Brigitt and her parents for care and providing all the information! I was happy to meet you Se & Bi at the last day in Florence - you're awesome ))