If you look at Samsonov last 10 games you notice that he is the best G in AHL right now and that he started to produce at the level we all expected from him. Don't forget he played extremly well in KHL for last three years. His 0.929% save percentage in KHL was fantastic for a young goalie. Only Bobrovsky, Vasilevskiy, Varlamov and Sorokin had similar results in that league at the same age. It took him some months to adapt to NA lifestyle, English language, small rink, etc. He will be the NHL Hall of Fame Goaltender.
It doesn't mean Vanacek is bad. His 0.897% save percentage over the three last seasons in AHL proves that he can develop to a decent AHL goalie.
Oh yeah, these guys are all the model of consistent and well-adjusted G's. A guy who seems to forget how hockey is played in May, a guy who literally had to ask for a vacation last year, a guy who can't stay healthy, and a guy who hasn't played a single second of North American hockey. Maybe not the best argument in the "rush them to the NHL, it always works out!" camp.
10 games is an insanely small sample size and for those 10 games there is also 14 games where he looked rough.
Why in the world would we ever push this guy before he's bursting out of Hershey?
We literally have buckets of talent in front of him and Holtby isn't potentially leaving until 2020 (don't even begin to tell me you think we should boot our Vezina/SC Champion goalie in favor of a guy with "potential").
Like seriously though, a team is a business, and if you look at all of your players as assets, why would you waste commodity like Vanecek (who has a shorter shelf life right now that Samsonov) simply because you're giddy about the future? If Vanecek gets the nod and spends time in the NHL one of two things happens, his value increases (which gives us a ton of options, keep, trade, etc.) or we see he's not that great and we can move on. What benefits do we get from pushing up Samsonov instead?
Do I believe Samsonov is our future? I'd like to. Do I think it's smart to throw away every lesson of development because he looked good in ten games? Hell no. I also once thought that Varlamov was going to win no less than 5 Vezinas. I also once thought that Holtby would be a first ballot HoFer.