Moulson's good but I wouldn't put him in Vanek's category, not by a long shot. Vanek's the best player Tavares has played with so far, look for them to light it up. With all the turmoil in the Eastern conference, getting Vanek could turn that 1st rounder into a 20th+ pick in a weak draft.
And you never know, the Isles might deal Vanek at the deadline if they can't sign him long term, he's worth a hell of a lot more than Moulson is, obviously.