adt, you are correct which is why I asked why you were thinking of Cambridge. The JBS program is not a quant course ) I hear tell they may do a quant MFE at some point but I can't find out when.
Apparently people take my opinions seriously enough that I'm not allowed to endorse MFEs, but the best MFE in Europe is the Part III of the Maths Tripos, (MMast) at Cambridge which is also the cheapest decent MFE on the planet, but...
a) it's not an MFE,
b) it's in Britain not Europe, and
c) with all due respect you will find the competition to get on it really quite tough
Also be aware that "England" and Britain are not synonymous, Scotland has some decent universities.
As for "transparency", let's be clear that there is very little of it from any MFE provider, they all flatly refuse to publish actual numbers that actually mean anything. As above I find the acceptance rate pretty much the most bogus metric I can think of for judging a course.
If there is a difference between UK MFEs and US ones is that I believe the UK ones aren't hiding, they simply don't have the numbers and don't care to put in the effort to get them. You can see that as better or worse. At least two well known UK programs don't track failed applications at all. Also unlike the US, most countries have some sort of data privacy law and it would be really quite tough to give pay numbers without starting an expensive nightmare of compliance issues.
Only if a non-American watches too much US TV does he really get joke references to the malicious unhelpfulness of the DMV.
No other country has that issue so the most trollish bloody minded and frankly awful people to have in your employ are to be found in British university administration.
To quote the head of alumni relations from my old school "I don't really like talking to people".
That's the head of a team of >4, that means there are >= 4 people that the school thinks are even less good at alumni relations.