Inigo's apartment is very comfortable and bright, which is well located for exploring San Sebastian. It is a 10 minute stroll to the beaches and the old town (pintxos!) It also has a number of cafes close by (including a great place for coffees and breakfast next door to his building) and a couple of small local food shops.
The apartment has everything you need and has very effective air conditioning too.
Inigo is a perfect host, providing great information about San Sebastian and is quick to respond with all questions and general communications.
I would recommend staying at Inigo's.