Th apartment is just perfect for a trip to Lisbon! The location can't be better if you want to stay in Bairro Alto. Its right in the center of Bairro Alto, just around the corner you'll find all the cool bars and stuff, restaurants etc. but you're still able to sleep with the window open. Also supermarkets and other nice districts such es Alfama etc. are within walking distance.
The apartments is rather small but you won't miss anything. The portable wifi is also very useful. We haven't met Paulo personally but everything worked great with the self-check-inn System (which is very useful so you don't need to carry any keys with you) and Paulo checked with us during the stay to see if everything is okay.
So altogether definitely a recommendation.