I recently had the pleasure of staying at the Tiara Park for a business sales conference.
Our company chose Porto primarily because of its proximity to a local manufacturer in Braga and because of the overall "value" associated with the hotel and the historic yet modern city.
We typically choose contemporary hotels but decided that based on the many positive trip advisor ratings that this hotel would be a "safe" bet (and location was not our primary criteria and generally it was only a 10 minute cab ride to anywhere in town).
Sure enough, it was pure satisfaction and the hotel management/staff did a wonderful job accomodating our every need throughout the stay.
I was fortunate to have checked in to their second largest suite with two upscale washrooms, a kitchen, dining room/living room and sizable bedroom with flat screen TV.
The suite was tasteful, well designed and cozy. If I had one little complaint, I would say that my mattress was a little stiff but that's probably a local thing based on my travel experience.
The hotel restaurant/bar and conference facilities were all well appointed, comfortable and offered quality food (BIG BUFFETS), beverages and service. You feel as though you're in a large boutique hotel with a pleasant aura of calm and charm. The staff exude a warmth that is almost "family like" and generally have good comand of the english language (but some better than others which was just a little frustrating at times).
We had the opportunity to hang-out in the lower level "club" on the saturday night of our visit and had quite a lot of fun although it's more 70's disco (if you like that level of action).
I would highly recommend the Tiara for business or personal stays and can reassure you that this well run hotel will go out of its way to provide you with a superior experience.
The city of Porto (although slightly run down) offers a wide array of historical venues and is extremely well known for its superior Port wines (both red and white).
Surprisingly, it also has a modern "west coast" edge to it and I was pleasantly surprised with the airport, concert hall and choice of world class "fusion/asian" restaurants along the ocean.

My only regret is that it would have been nice to spend a few more days in Porto......

Like many buildings in Portugal, it doesn't look that promising from outside, but inside everything was elegant and tasteful, whether in common areas or our guest room. If you don't have to have sea or city views, the location is possibly a good compromise. The biggest minus was the lack of free or truly affordable parking. Of course, one could presumably do as the locals and simply park in the middle of the street, blocking traffic. Our room was in impeccable condition, very comfortable and well appointed. The bathroom was also very nice. My only complaint about it was the half shower door that is so common in southern Europe, and the necessity to use the hairdryer outside of the bathroom. The pillows were probably the most comfortable I've ever had at a hotel, and the bed was reasonably comfortable. The bed linens, bathrobes and other textiles were very nice. We didn't realize the hotel had a fitness room, so we didn't bring our workout attire, but they have what appears to be a fairly small fitness room just off the main lobby area. We only discovered the breakfast buffet on Sunday (our last day), and it was quite nice but rather expensive at €21 per person - especially compared to the €3.50 we spent on breakfast for two the day before at the little stand-up cafe inside the supermarket across the street.

Annual trip for 8 ageing lads was to Porto this year. Interesting place - very hilly, run down in places but picturesque. River area was very nice with magnificent views of the bridges (suggest you walk over the main one - stunning scenery - cable car the other side which takes you down to the river - E5) and some nice bars and restaurants. Strongly suggest that anyone going to that area (Ribera) try the Ode restaurant. Small place, not cheap - but food and wine is lovely. Meal is not quick but that is because Christophe - not sure if he is the owner - takes time to explain where he sources the food from, why he chooses certain products and why he picks the wine and other drinks he sells. Extremely interesting and entertaining - a really good evening. Bit disappointed in the lack of things we like to do apart from the sightseeing - ie: watch some sports in bars, odd game of snooker/pool - seemed to be dominated by small street cafes and very few ordinary bars as far as we could tell. the Tiara is a nice modern hotel with good rooms and facilities. Nice bar area with a tv lounge where we did watch some football and had a chat with staff and guests. Staff were very helpful and pleasant - as were most of the other people we met in the town. We walked into town on the first day but it is a long trek up and down steep roads - highly suggest a taxi for all trips - with 4 of us in a tax it came to the princely sum of E1.50 each - or get a bus - I couldn't find the metro station. Same to get back to the airport - cost me as a single traveller E17. Visit to the port warehouses is a must - we went to Taylors and had a tour followed by an excellent lunch with nice wine and needless to say, many glasses of lovely port. Good weekend but not sure if I would go back to Porto for this kind of event - a bit too quiet.

Excellent hotel, little bit too far from the city center.