Our stay in Lisbon at Gonzalo's place was wonderful! The apartment is very centrally located with easy access to wonderful bars, restaurants, and cafes. I was not totally aware that the entrance to the apartment was in a back alleyway, which may have been my own fault for not thoroughly reading the description. This was no issue for me, once we figured it out on a map, but I may not have been comfortable as a single woman traveler and certainly would not be suitable for anyone with a disability or trouble walking.
Aside from that, the flat was amazing and stocked with everything you'd need. Highly recommend for your next trip to Lisbon!