I find that a stat like GSAA is the best at talking about which goalie had the best overall season for a few reasons:
1. It's a counting stat, meaning you either need to be consistently exceptional (Like Hutton), or you need to be above average over a long period of time (Andersen, Gibson, Rinne).
2. It takes into account expected sv% and actual sv% (dSv%) which takes into account the low/medium/high danger chances a goalie faces and averages it over what the rest of the league is doing. By doing this it makes it show you that when a team is artificially lifting a goalies basic stats (sv% and gaa) it's actually more of a product of the team, and not the goalie being exceptional. For example, Dubnyk has been a 15-20 ranked goalie for years, but his team has been so good at suppressing HD chances, he has looked much better. This season we can say that goalie is Tuuka Rask (sorry) because the team in front of him this season has made it exceptionally easy to be a goalie in that net.
Basically I don't like the idea of Sv%, Wins, and GAA being the main reason a goalie wins the Vezina. It's obviously not perfect yet, but I do feel like dSV% and GSAA are much better at talking about WHY a goalie is good, where as I believe Wins/GAA is more team driven, and sv% doesn't tell the full story.