Passing Core exams v. Graduating LSE Msc w/ distinction

[Bigdan1010]

I am wondering how the difficulty of passing core exams at a US PhD program would compare to graduating from LSE Msc program with distinction. It seems like, if you are taking the Msc research route to at PhD at LSE, graduating with distinction is basically the equivalent to passing your cores. I know less people get distinction, but maybe that is because not all the Msc students are trying to pass onto the PhD program so they do not try as hard for distinction? This is just speculation.:D