I actually use most of the words included in the test (though I will admit that I have English teaching background in the States.
) with my American friends. Some of the words, however, are quite peculiar, such as “dowager,” which, to my experience, is almost exclusively used in British English. It was quite funny when I sent it to my parents when I found it the first time; my mother, who never went to college, scored over 28000, while my college-educated father (who is also a teacher, though not of English) scored around 20000.
It’s fascinating to see how retention and learning of vocabulary differs from natives, but it also proves how skeptical we should be of Japanese natives at times when asking about word usage. One of my 国語 teachers who looked over my shoulder while I did the Japanese test didn’t recognize one of the 四字熟語 answers at the end!
If I remember correctly either “alacrity” or “alacrious” was in the English quiz (also noting the auto-correct for this site doesn’t accept “alacrious”). It may be less commonly seen, but anyone who played League of Legends up until, I think, two years ago, could definitely tell you what the Alacrity boot enchantment did! 
I’m quite certain one’s interest in literature is by far the most determining factor in vocabulary range indicator. Even video games often employ more obscure words for “style.” I’m finding that out the hard way with Japanese games!