The hosts were terrific, very helpful both prior and during our stay. The flat is only 250 metres away from Rossio Metro station and around 12 Metro stops from the airport - get a travel pass at the airport. It is much cheaper than paying for each and every journey. A pass for five days costs around 30€, great value. No need for taxis. The flat is very modern, stylish and light. We were impressed. The bathroom is marvellous, with a huge walk in shower. It is fully equipped for cookin, fridge, TV etc. With so many great cafes and restaurants and outstanding food we did not bother cooking, choosing to eat out instead. You can eat better in Lisbon that almost anywhere I know and the prices are very reasonable. The flat is located in a one of the most humble areas of the city. The immediate population has a significant proportion of new arrivals, Arabs, Indians etc but it is very busy and quite safe. The Baixa and Avenida district is on the doorstop with lots of cafes, restaurants and shops. It is only around 12-15 minutes walk from the Gloria funicular and the Santa Justa lift taking you up to the Biario Alto and Chiado. The Rossio railway station, taking you to Sintra, is about 10 minutes walk away. The Cais do Sodre railway station, for Belem and on to Cascais and Estoril on the coast is only two Metro stops away. It is only a 15 minute walk to the St Jorge castle and the Alfama district, so the location in excellent. I can heartily recommend this flat. It offers excellent value for money.
A tip: bring some sugar and tea/coffee with you. It is pointless buying them in the supermarket and bringing most of it home in your luggage.