I am currently looking to book a place in San Sebastian on Homeaway.com has anyone used this site before?
Yes, I used it to rent an apartment in Verona. It's just like VRBO. No problems for me.
Homeaway is based in Austin and my cousins have used it for a holiday rental. Am sure like all home rental sites you have to read all the details, look at Google maps, do all the due diligence.
I have used it for rentals in the US with good success. You usually deal directly with the homeowner.