I stayed at Econo Lodge Dar es Salaam for more a week and never considered changing the hotel (although I changed my room, moving into an air-conditioned room after the initial two very hot nights).
The rooms were surprisingly spacious and very clean.
All the essentials were there (especially a hot shower and a toilet, and mosquito netting at the windows); some useful extras were missing (for example WiFi), and there was neither a TV nor a fridge in the room.
But at a price of less than 15 Euros for a non-air-conditioned room you can't expect that.
The staff at the reception were very helpful and reliable (you can leave your valuables with them without any worries), and so were the cleaning ladies.
Please do not stay here if you want everything to be perfect. At 35,000Tsh for a double room in central Dar (at least inside the Bibi Titi ring road) you are not getting luxury!