This hotel is in need of a little TLC, but it's okay, generally speaking. Housekeeping services seemed to be somewhat lacking - e.g. the floor was not clean or swept properly. The bathroom was incredibly small with hardly enough room for one person to move freely. The bed was comfortable and the bedding and pillows okay.
They have a great rooftop garden and restaurant, serving good local food (including a preset menu at a reasonable price). The rooftop has a good view of the street. The people/staff were friendly, but we didn't interact with them much save for the server at the rooftop restaurant, who was quite pleasant.
Hotel Principal is an old, budget hotel ... charging relatively high prices for budget accommodation and services.