I have stayed for a few nights while on an official trip to Tehran. The hotel is located some 45 minutes by taxi from the Grand Bazaar and is right next to a major road. This means a lot of noise around the clock also due to the fact that the windows are not soundproof.
The hotel itself has probably seen better times although the staff try to make it appealing. It is also a bit overpriced for the services it offers. I have paid some $130 per night for a single room. Otherwise my room was basic but clean. Internet was also quite ok all things considered. Travellers to Iran should be aware that not all sites are accessible on the net.
The staff are kind enough and will try to help you as much as they can.More