Lovely place! I've been there for a weekend and got really surprised by the location, cleanliness, decoration and hospitality of the host.
With just a 5 minutes walk you can go to a lot of historic places like Praça do Comércio, Praça do Rossio, Elevador de Santa Justa, countless churches or, if you are not interessed in history and architecture, the street pubs of Bairro Alto (but I bet there's history there too).
I highly recomend this place and will definitely stay there again.