I have completed the MSc QF at ETH Zurich. It was definitely a good investment for me, and got me into a great front office job. The degree is definitely very academic and theoretical, but you could argue that it's better to learn theory at uni and practical knowledge, well, on the job. Most people who work in quantitative finance come from a maths, physics, computer science background, and these people always know ETH. It's a science powerhouse, which spit out great minds like e.g. Einstein.
I would be very careful with rough judgements. Oxford is obviously a more widely known name, and every grandmother has heard of it. But this Oxford master and the Said school in general is definitely not one of Oxford's highlights, but rather a commercial sidearm which brings in some money for the poor academics. It is less selective. In contrast, the master at ETH is highly regarded at the school itself, and it is offered like any of its other degrees, at very low cost to the student. The cost of the program is actually higher at ETH than at Oxford, due to the higher number of classes and professors involved, but the costs are all covered by the huge federal budget that ETH receives from the government.
I agree that if you look at things long term, then the tuition starts to look less relevant, but getting a lesser degree AND pay huge tuition => I would bite my toes off.
If you want to work in London, then Oxford's proximity probably comes in handy, but any decent IB will pay your flight tickets for interview sessions, so I would not place too much value on that. And anybody who can feel the cold wind from Brussel's anti-bonus regulation against London knows that Switzerland is the new place to be.
If you are from the EU, then you don't need a working visa for Switzerland. If you come from outside (China, India...) then it similar to the UK or US, i.e. you need a company that is willing to sponsor you.