This is very conveniently located if you are visiting the ExCel and is about 1/3rd the price of a hotel.
But note that you are just renting a room, nothing special - essentially a bed, storage and Wifi. It is a large room, 5th floor and is quiet, so if all you want to do is sleep before or after going to Excel then it is perfect.
There is no access to shared areas - i.e. a kitchen for coffee (you can buy a Costa from Tesco next door) and if you are a business person then make sure you iron your clothes before arriving as there is also no access to an iron.