We had a fantastic stay at Martin's apartment. I highly recommend staying here. First, the location is ideal It's near all the action with great restaurants, bars, and shops all within steps of the apartment. However, because it's on the 2nd floor, we did not hear any of the street noise.
The apartment itself is really well decorated and had everything we needed for our stay. The kitchen was a highlight - new, modern, large refrigerator, and everything you need to cook a meal. We loved the bathrooms -- the showers were great with plenty of water pressure. The bedrooms were perfect for our family of five. A huge bonus was the elevator, which made taking luggage up and down very easy.
Martin was great with great communications throughout our stay. Check-in and check-out was a breeze. I would definitely stay here again when visiting Lisbon.