Hotel San Sebastian—while clean was overpriced.  The room was small (and nothing special) and the location is away from the main part of town.  This is not a big deal (in fact my girlfriend and I enjoyed walking when we did and otherwise it was easy to take a bus) but the hotel was not priced for this fact.  In addition, the hotel charges us for having 2 people in the room as opposed to one.  While I can make an argument for while a hotel is entitled to do that, Hotel San Sebastian charges us €50 additional.  We thought this was unfair.  My girlfriend and I would definitely stay elsewhere if returning to San Sebastian.  
 

Due to a major concert in San Sebastian, this was the only available hotel in town so we did not have any other choce for the night in question. The room was large, clean and comfortable, but the location is not the best. If you are in town mainly for laying on the beach it is probably ok as one of the city's three beaches is only two minutes walk away. It will however take you about half an hour to walk to the city center and old town and although you can walk along the beach it is not ideal in my opinion.
I did not find the staff rude as other reviewers have mantioned, but they were not particulary nice either. I do not think I saw even the slightest bit of a smile on anyones faces.
Breakfast was expensive and nothing special. I recommend walking along the beach to cafe La Perla (approx 15 min walk) for some pinxos and fresh orange juice instead.

San Sebastian is a fantastic city, well worth a visit, but I'd give this hotel a wide berth unless you are able to get it at a VERY cheap rate. Rooms are comfortable but quite basic, although our room seemed to have lots of things wrong with it, aircon - not working. English language news channels - not working. Wifi - sporadic at best. We also had power go out on our entire floor 2 nights running, dodgy electrics?!
The breakfast is also a complete rip off, €29 for both of us, think sweaty sausage in a warmer and snotty scrambled egg. And lots of cake.

Location-wise it's ok, pretty far from town but an easy bus ride, and the beach is only a 5 min walk away.

Watch out for the staff, they are a grumpy bunch!

Well located hotel close the Ondarreta beach and at the heart of Antiguo, you will need additional transport to visit the city center and the Parte Vieja (Old town). In spite of this service is professional and helpful and if you have no other choice the restaurant is a correct one. Hotel facilities and rooms are a bit below the four starts that it shows on the main gate..