We've had a georgious time at Lisboa. It's a lovely city.
I could recommend Catarinas apartment absolutely. It's cozy, central and clean. You can find everything what you need round about the house (little supermarkets, restaurants and a lot of bars). Especially for going 'on party' it's well located. Although the nights in Bairro Alto are long, the flat is totally calm if you close the windows - no noise. So you can have a perfect mix of getting in touch with Lisboa nights (if you want) or you can have time for yourself - perfect.
Nearly everything we've seen we've walked to. But if you don't want to walk you'll get to a metro station within 10 minutes.
The communication with Catarina was very easy and always with helpful advices. Thank you very much for these days!