I stayed here in a business trip and liked it very much. Good rooms, with lots of space. Very comfortable.
The breakfast was very nice and served until 11am witch let me have some more time of sleep. Very central. I recommend it.

Good room, great view from the bar (17th floor), warm staff.

The hotel's handicap is that there's nothing to do nearby and it is still 1km away from the city centre.

I stayed here for four nights and really, enjoyed my stay. In response to some of the earlier comments, I would like to say... the quality of room was excellent, very clean, a really comfortable bed and the shower and A/C worked well. The staff were all very friendly and the bellboys were always around and helpful. I ate in the hotel restaurant most nights and found the quality of the food and service to be very good. There was a good range of food for breakfast and everything was kept topped up.

It's not in the most central location but it is really only five minutes walk to Avenida dos Aliados and Trindade Metro station - which is useful as it connects with all the Metro lines, including the new north/south line to get downtown (two stops). It is also very easy to get to and from the airport. It's a pleasant 15 minute walk to the main restaurant area.

The only thing to improve in the hotel is the WiFi, as the charges by the provider (swisscom), of 8 Euros for an hour / 11 Euros for 24 hours, are very expensive for 2011. There is publically provided free WiFi in various locations around Porto though.

Would I stay there again? Most definitely , yes.

First impressions of the hotel are not great, it's a slightly tired looking tower that dominates the otherwise historical architecture of Central Porto. The awning on the front of the hotel was very dirty too (thick with bird droppings).
Inside, however, the hotel is bright and clean. My room was on the 14th floor, the view was stunning. The rooms are very clean and nicely furnished and the water pressure in the bathroom was great.
The breakfast was ample, a self-service buffet offering a mixture of breads, pastries, eggs and bacon.
The bar on the top floor is perfect for evening drinks, it has the ambiance of a 1970s cruise ship (which I loved). There is an outside terrace which surely has the best view of the entire city.
A great base for a holiday in Porto, highly recommended.