Well, I somehow was expecting that the upgrade would happen automatically, but one has to download it explicitly from steam. Not a bad move if that holds true for versions to come based on DX11, which won't work for those still on XP and Vista, so, they will not end up with a GG unusable to them.
I had a full go through Morning Mountain Stroll, start to end. Although the Overall increase in framerate wasn't that great for me, a General Feeling that everything is a noticeable bit more fluent (which usually means at least 15% Performance increase) is definitely there (system specs: GTX980M, core i7-4710MQ@2.50 GHz, 16GB RAM, Win 8.1-64)
Also on the good side: I died a lot on incoming RPGs, but never had to face the dreaded "Floating grass" again at all after being resurrected.
And my other quirk with RPGs is at least remedied a bit: whereas the Rocket men formerly obviosly didn't have to aim at all but just needed to shoot in My General direction to kill me, 5 out of 10 of my rpgs used to pass right through the enemy or exploded right at their feet or at an object next to them without doing
any harm to them. This is no longer the case.
The cooling fan kept much calmer and quieter than before.
So, the update is looking promising so far, and it seems that good things were done to GG in much more than only the performance Corner.
Were there any Problems: Yes, but tiny ones.
1) a very occasional texture flicker I never saw before with M.M.S.
2) Pressing "T" to replace a weapon Held by another weapon type just found did not work
3) also very occasionally, my first and second shot were fired soundless.
Well Done, GG Team
Oh, last but not least : .fpm release is still 308, so I can happily continue my work on my two humble Tools.
Lives of great men all remind us we may make our lives sublime