Well, if you were excited by "Global Illumination" then I hope you have a PHD in understanding a massive amount of confusing shit.

I, naive, thought it would come with "Turn Global Illumination ON" button and that would be the end of it.  Or, perhaps, a different kind of light.

Nope...it's a labyrinth of nonsense that the "Experts" are bickering about endlessly, tweaking this and adding that and nobody seems to agree on how to make anything look totally good with this "GI" which as far as I can tell, involves making props that emit light, and using no actual lights in the scene.

Is that what GI is supposed to be???

Without this, about the only thing I've noticed is better render speed.  Meanwhile, things are crashy as per normal when something is new, and by the time they fix everything I expect to see a decrease in this speed gain.

It's just how things usually go.