There are 2 floors in the apartment comunicated by small spiral staircase. The bedroom is nice and has beautiful river views. The kitchen has a low ceiling and a small window but is comfortable. However, the bathroom is very small and 2 people together can't be inside at the same time.
Another thing to say is that if you go with your car, you'll have problems to find a secure parking in Alfama, Baixa-Chiado and Bairro Alto (maybe less problems in Bairro Alto). Besides, the price of parkings is high.
Appart from that, we enjoyed in Lisbon and Sintra. Lisbon has spectacular views and its old town is pinturesque. There are many trees in the city because they've respected them and this fact I like a lot. Sintra has 3 main monuments and amazing forests which you have to visit. I recommend you.