We stayed at the EMAJ Boutique Hotel in February. Originally, we planned to stay one day but decided to extend it another. The hotel is beautiful, their staff extremely helpful, and Guimaraes a great town. The hotel location is superb, overlooking one of the main squares, close to all the attractions.
Breakfast is good by European standards (pastries and coffee). Parking is limited to three reserved stalls on the street. WiFi had some trouble in the rooms but was great in the main area (was being fixed during our stay).
Overall, the experience was great and we would love to come back!