I have been at the Heritage in august 2010. The hotel is clean and structures are new. The room are spacious and have air conditioning. The location is perfect if you are to pass some days in Dar and/or move to Zanzibar via ferry (you can walk from the hotel to the ferry). Many relevant places in Dar (such as Nyumba ya Sanaa, the National Museum, the Botanical Gardens, the Posta bus station, the Askari monument) are within reach without the need to take a taxi; since it is in the very centre of downtown Dar, there are many shops all around including bookstores, drugstores, supermarkets, banks, bureau the change, pharmacies and whatever else you might want to find in Dar. Service is good although the staff is sometimes a bit unexperienced and some details are missing (e.g., they are not very effective in helping you around - bring your own map of the city if you want to go sightseeing). You can only pay cash. The restaurant is outsourced to the nearby Albasha restaurant, which provides a decent breakfast and might be OK for a quick fast-food-like lunch, but it is not outstanding and I would not recommend it for dinner. The hotel provides transfer from/to the airport at the cost of 25.000 tsh (20 USD) but just outside the hotel's door you will always find taxis waiting and they can charge less if you bargain. It stands quite close to a mosque so you will hear the muezzin singing relatively early in the morning, but not so loud as to prevent you to sleep if you need to.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.