The apartment was extremely clean. There was great communication too, you can call them if you need anything.
There was a little hygiene kit with things you will need for the kitchen & laundry. That was very helpful.
Keep in mind that you need to bring cooking essentials (oil, salt, pepper, etc.) if you want to prepare any meals in the appartment.
Free Parking in the streets of San Sebastian is very scarce and public parking costs around 25€ for 24h, so it may make sense to book their parking service. All in all, a very good experience!