greater feat? I am not sure I follow. Sandy Komito had access to Attu, and even with the small number of splits since Komito's big year, I still would say Sandy had an advantage that later birders don't have.
Edit: for my money I am more impressed with Kenn Kaufman's big year, or Greg Miller's
What I was mostly thinking of is the huge advantage conferred on the modern twitcher by improvements in communications & public recording (most notably the cell phone revolution & ebird). I admit, however, that Attu is a fair point on the other side.
According to post #117 Vanderpoel was at 744 earlier today, one shy of the record. Is that what he finished with?