The flat is really well located, very easy to get anywhere, including walking to Alfama and the train from Rossio to Sintra was on our doorstep! It was clean and much bigger than it looked in the pictures. We loved the balcony around the entire flat, and the lovely floor to ceiling windows which let in so much light! The bed was also huge and very comfortable.
There was some music that could be heard on Saturday night from a bar which is on floor 2/3 of the apartment block. This didn't bother us as we live in central London, but might be an issue for very light sleepers as the music went on until early morning.
overall we had a really lovely stay and would definitely come back!