First of all: visiting Lisbon in general is one of the best ideas you can have!
Even better if you can combine your trip staying in Miguels charming flat. Perfectly located right behind the beautiful Basilica da Estrela (with its park one of my favourite spots of the city).
Lapa, the neighbourhood is central, yet quiet and everything is easily accessible by walking.
Miguel repsonds very quickly, very friendly and is very cooperative and helpful when it comes to special wishes (e.g. different check-in times, etc.)
The apartment was very clean, well equipped and as shown on the photos. Highlight is the big terrace! Another nice detail: Miguel created a magazine with some very good tips for exploring the city!
My recommendation: visit Lisbon as often as you can! And by staying at Miguels flat you are doing nothing wrong!