Awesome place! Everything you might want in a lovely city of Lisbon.
We stayed at Philippe's apartment for a week in October. We didn't get to meet him in person, but he was quick to respond and easy in communication. He also seems to be a thoughtful person with a great taste! Susana, who welcomed us at the apartment, was really helpful, nice and punctual and made us feel at home.
Location is great, you can reach all great neighborhoods by foot. For Baixa and Chiado you go down the street, for Graça and Alfama - up the street. Supermarkets, pharmacies, banks etc are all around the corner. Transport is also super easy: there's a metro station and tram stops nearby, and a taxi spot on Largo de Graça.
The apartment itself is really a great one - styled with great taste and care. The view is probably the best in the city, especially at sunset and at night, pictures don't do it justice! Of course, it comes with a price of climbing up the stairs to 5th floor, but it's so worth it.
There is everything you need in the apt: full kitchen with dishwasher, air conditioner, plenty of seating and lounging options, a comfortable bed and bathroom with shower. Towels and linens were nice hotel quality, which is not always expected in a bnb:)
Bad parts? Probably all the climbing, both around the city and to the apartment, but you forget about it as soon as you look out the window :) Construction outside the terrace is creating a bit of noise, but only on weekdays and during working hours, so not really a bother. They look like they might finish soon, so the view might get even better!
The area near Martim Moniz metro can look a bit dirty/shady, so you might want to be careful, though nothing has happened to us there. And look under your feet, dog owners don't always clean up.
Local food is decent, but service may be lacking sometimes, getting a smile from a waiter is considered lucky :) Don't miss out on local cafes with pastries, they are all amazing. Definitely go to Belem - we went there by train, it's very fast and convenient with just a metro card. You can also go to Cascais, beautiful town nearby with relaxed atmosphere, beaches and ocean views if you get tired of the city.