Great and authentic location if you want to stay in the historical city center, but the apartment is extremely small, not for a long staying. Photos are a bit different from reality, it's not so critical, but the sofa is required to be cleaned and repaired.
The host is very friendly, with clear directions, and recommendations.
Also, pay attention that in historical buildings terrible soundproofing.
During WebSummit all prices in Lisboa are overrated. Book in advance.