I have views from both sides. The UK has some good schools but not all of them and the same goes for spain. It all depends where you choose to go in that country. From my personal experience i cant fault the training i received in Spain many of my friends completed in the UK with very established schools and received a lower standard of IFR and commercial teaching than myself.
At the end of the day its your own choice visit the schools and speak to the instructors and you will make up your mind from that.