I feel like this decision is so close because I can see both sides of the argument and agree with both. The only problem I have with giving it to JohnQT over valyn is the fact that after Masters Madrid we saw valyn (and consequently G2) step up in a big way leading to them being the 3rd place team from NA headed to Shanghai. Not only going but placing 3rd in the international tournament over the NA winner's 100T.
At that point I would have still said JohnQT was IGL of the year considering they are both in their 1st year as tier 1 IGL's and JohnQT immediately helped his team to win a national and international title. But as we look at today's team rankings and how both Sentinels and G2 have played I'd take valyn over JohnQT.
Sen has slowed down as a team who was running through their opposition and looked like they could be the best NA while G2 has made the steady climb to being better and better with each series. Now yes they lost in the finals 3-1 but the fact that they were able to consistently place 2nd-3rd in 2 national tournaments and 3rd at an international while Sen has been more volatile is the reason I take valyn over John right now.