Crosby 07: Won the Art Ross by 6 points, 20th in the league in goals, 51% of his production was on the PP
Crosby 14: Won the Art Ross by 17 points, 7th in the league in goals, 37% of his production was on the PP
McDavid 17: Won the Art Ross by 11 points, 26th in the league in goals, 27% of his production was on the PP
McDavid 21: Won the Art Ross by 21 points (would have been 31 points if full season), 2nd in the league in goals, 35% of his production was on the PP
It’s also worth noting the league wide scoring levels are extremely similar comparing the 2007 Hart to the 2021 Hart and the 2014 Hart to the 2017 Hart.
I think looking at that I’d vote for McDavid because the 21 Hart win was clearly the most impressive (only unanimous win, highest goal scoring finish, and largest gap over #2) along with the fact both of McDavids wins were done more at even strength