I myself went to school in spain and in the uk. I loved being brought up in spain, especially my teenage years as it is more of an outdoor life what with the pools and beaches, where as when we moved back to the uk when my sister turned to her teenage years she did not know what to do with herself as there is no where to go for free in the uk. And its always cold and raining.
She hated coming back to the uk to be honest and I personally would have hated being a teenager in the uk.
I moved back to spain and we had children, they went to spanish school. The fees were really low compared to the uk so we went for private. The school was great, the only thing I didn’t like was the fact that they were forced to do everything in catalan (as I was at school) and only one spanish lesson, so they mainly spoke catalan, which I found to be quite narrow minded as we were in spain after all, but that was just my opinion.
We are now back in the uk and my kids go to a village school which is really good and the children are all nice. The only reason I came back is because I was worried about their future in Spain. It was great to be out and about with your friends in Spain but when you left school there was not much career wise going on. But that was mainly down to the fact that we were living in a beach resort. I find there is more culture in the uk, it is more up to date with everything where as Spain is very behind. I will always be split between the 2 countries but I would advise you not to live too far from a large city as when your children do leave school they will find it hard to start a career in a beach resort or similar. The only jobs you can get is bar work so not much of a great career for them unless they start their own business as I ended up doing, or I too would have ended up being a waitress working only 6 months a year and then unemployed in the winter, which can be quite a depressing prospect. Definetely would advise 100% you to rent first. If you don’t you are mad, you can never know what an area is like until you have lived there. All the best.