Happy new year to you Mark and I hope you had all your 12 grapes.
As, I have indicated in the past, prices may go up or down, If you have bought the right property at the right price/location you cannot go wrong.
(ignoring the speculators who will find another so called hot spot) If you buy to nest/quality of life and have the staying power there is no problem.
The argument of price falling 10%, etc is purely academic. As we the forum users know the valuations is a hit and miss, the land registry figures cannot be relied upon for reasons of under declaration and Spanish attitude of not being precise. So the pasa nada attitude distorts the statistics further.
I think long term rental could be an issue as the owners would use the property for themselves, family/friends from time to time. As there is no real buy to let market due to law being biased towards the tenants/court delays and tax issues for non residents. I cant see the rental market evolving into a proper sector for years to come.
Happy new year to you.