To sum up: awesome! We arrived from Miami Airport, thanks to Inaki's tips we had no problems getting from the airport to the flat. Upon arrival, Inaki warmly welcomed us and gave us loads of insights about good restaurants and places (off the main tourist tracks) to visit - we didn't have time to follow everything, but we had a fantastic time with the places we visited. My girlfriend and I were actually surprised about how much cool stuff there is to do in the city! :)
The flat is very clean and the view, especially in the morning when sun rises, is breathtaking. In the evening we also enjoyed some red wine on the balcony, which was nice. Inaki also has a large bathroom with integrated "jacuzzi" - it's the first time I did one with (almost) cold water as it was very warm outside. :)
The amenities inside the condo are also top notch: you got a well-equipped gym, a 50m long pool (the best is that the neighbouring buildings are not hiding away the sun - something quite rare in the center of Miami), valet service, spa, sauna etc.
Close to the flat you can find in walking distance all what is necessary, from restaurants to supermarkets, coffee shops and bars.
There's also a nice park just in front of the building. The Heat's stadium is also in walking distance as is the museum for contemporary art.
So me and my girlfriend were very satisfied and we'd certainly book the flat again upon our next visit to Miami (hopefully soon) :D