In the past few months, Leafs fans have discussed every possible permutation of trades involving the Leafs pick. I've long been a proponent of the following (very general) draft strategy:
1. In the top 10, stand pat
2. Outside the top 10, trade down and accumulate more picks, unless someone you really like has slipped
Of course, this is a generic strategy, that can't be applied to every situation. I certainly wouldn't have traded down from 17, because I REALLY like Kyle Connor. But on average, this is a strategy that works. Draft value decays exponentially, as has been shown here by (first) Chemmy.