I imagine there are lots; this has been raised as a possibility for my DD.
It's very speculative & there are loads of things I don't know but:
Advantages
It's Spain!
It's Barcelona!
It's exciting!
She'll learn about another counrty
She'll learn another language (properly)
It's amazing!
Disadvantages
No UK student finance
Presumably no Spanish finance
It's miles away - travel costs
Living in a big city
Another language - GCSE Spanish probably won't cut it
She won't build up the contacts in London that she would build up in the UK
Questions
Would she need health insurance?
umm so I guess it's a heart vs head thing but what haven't I thought of?