Inigo is an excellent and very helpful host, even loaning a bus card which saves €5 and is really handy to have. Very fast communicator and accommodating.
The location can't be beat; only two blocks from the beach and in the other direction some terrific pinxto bars (and further along, an amazing seafood restaurant called Ondaretta). There's a very good range of shops on the next block too.
The description is completely accurate--it's humbly furnished but perfectly fine, and in San Sebastian you won't be spending much time indoors. Terrific trip and place to stay.