I stayed at this property last month. The location is not great, but the metro and buses are not that far, and most evenings we took a taxi into downtown.
The clounge seems to be very short staffed. They only had one guy working there the three days I was there. He was there in the morning and late at night. Needless to say, he had a very hard time keeping the lounge cleaned up and food served. He also took away everything at the extact appointed time. So if you show up a minute after 10am there is nothing out for breakfast (actually even if you show up at 930 there was nothing since he was busy trying to clean up the place). The clounge still has a computer for free.
I did have trouble checking in and out (they kept trying to change the price of my rooms) and we had issues with housekeeping. They put the extra pillows on top of the unit with the tv which had a light on top--this led to the pillows being singed--a major saftey issue in my mind. Housekeeping also kept leaving stacks of pillow cases/sheets/towels in our rooms.
The front desk kept trying to stear us to expensive and touristy places to eat. Better off going to old town and just finding a place.
All in all, I will not be staying at the Lisbon Marriott on my next trip.