Fair enough! Sounds like you've got a good few options in mind! I'm sure you'll have a great time whichever one you end up choosing!
I've actually been studying Physical Geography - it's been a fantastic experience and the education has been second to none! I've been at university more or less every day and with almost all theoretical elements we've put into practice in one form or another with fieldwork and excursions - I honestly don't think there's anywhere in the UK that would compare. I've been all over the south of Sweden, done an exchange to Svalbard, worked aboard ship and surveyed all four corners of Rwanda, all financed by the university! It's felt like a proper education!
On the social side, as a non Swede it's personally been very easy to integrate into wider student life... at least for the most part amongst other natural science students but also beyond! The nations in particular are fantastic opportunity to meet new people, Swedes and internationals alike!
I think the biggest social difference compared to university in the UK is that most people take a year or two out after school (of which they finish at the age of 19), either for military service or work - at leadt from my perspective and ignorance to what uni is like in the UK, the level of maturity is slightly higher as a result. The majority of international perhaps unsurprisingly are exchange and master students.