The apartment is fantastic. It's modern, clean, equipped with everything... And it has big, panoramic windows that give you a great view of Panama City from the 10th floor. Some nice touches such as the free Panamanian chocolates and coffee and rum was very nice and appreciated after a long day travelling.
However, you should be aware that this is situated within the El Chorillo neighborhood, which is considered one of the most unsafe. My airport taxi driver warned me to "be careful" when he dropped me off. That said, you're only a 5-minute walk from the Casco Viejo area which is very tourist safe, and I didn't experience anything to make me feel unsafe. I was there two days as a solo traveller.
Minor complaints: The drains in the bathroom smelled funky, and I couldn't get the shower to produce anything except cold water.
Despite these minor annoyances, I would still definitely book here again. Very, very cool apartment.