As others have noted, the stairs are daunting, the place is old, and there are some doors and lighting to navigate your way through. I stayed alone at a rate of 1,200 crowns, which I thought would be a reasonable price for a single in such a good locations. It was adequate at best, but compared to similar properties in Prague, the rate is pretty competitive for an en suite. I was not asked to pay up front; I was told I could pay at check-in, checkout or whenever. I paid the day before checking out, and dropped my keys in the mailbox since I was gone before the reception opens at 9 a.m. The staff was all very friendly and accomodating - no complaints at all there.
My "single" I assume becomes a double when there are two people staying there. There were two very-much single beds, which were quite old. A cheap table and two cheap chairs, which were too low for the table. A fridge (would have been appreciated if I needed it), couple of glasses, utensils, chunk of soap, bath towel and bath mat. The room was clean and the bathroom was perfectly presentable, tough the shower was tough to handle as the shower device is handheld with no wall-mount.
My room (43) was in the middle on the top floor, so there was minimal noise from outside or from the neighboring rooms. As there's no TV and no WiFi, I got to bed early and woke up early after a sound night's sleep. Since it's just a minute or two from the Old Town Square, I got to enjoy the gorgeous expanse before the throngs of Dolce-clad Italian schoolboys and packs of German retirees, etc., descended upon it starting at about 9 a.m.
Back to the Tara - I wouldn't recommend it as it is nothing special other than the age of the building and the good location. If you have a day or two in Prague, it's a good hub though as you can enjoy the city's central historical areas without having to use anything but your two feet.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC