Now that you mention it...
Although, to be fair to Leon Russell, the ""real" changes to the A-section of "Angel Eyes" don't follow the minor chord w/a chromatically descending 7th pattern that "Masquerade" has. But other than that...
First time I ever heard "Masquerade" was as the B-side to a Carpenters 45 thea my kid sister had bought. This would've been 1972 or so, iirc. I remember thinking that it was a surprisingly hip tune (and arrangement) for such a treacly group. When the Benson version hit, I was pleased that such a nice song of recent vintage was becoming so popular. 30 or so years later, yeah, it's "overplayed", to put it mildly, but under the right conditions it can still be a satisfying call on a gig, which is more than I can say about most hit songs from the same era.
Too bad Gene Ammons never recorded "Masqerade". An A/B of that with his definitive instrumental reading of "Angel Eyes" (for vocal, I still gotta go w/Sinatra's on Only The Lonely) would certainly have been interesting.