This update has FINALLY fixed most of the problems I've been having since the February Lollipop update. It still lags and hesitates some like it did back on KitKat, but not nearly as bad as it was. Just about everything is working better.
I'm still ticked off that it took so long to fix. That's 5 frickin' months, almost 1/4 of my contract length I've had to deal with a POS phone. That's not acceptable. But, at least it's back to "normal", which still isn't great but at least I am no longer feeling strong urges to throw it against a wall.
Now the brightness works better in most situations, although now as mentioned it actually doesn't dim enough. It connects every time to my Pioneer deck where it rarely did before. Battery life is better and it doesn't start randomly draining it. And it doesn't have 3-5 second delays switching tasks or going back to the homescreen. My sanity is saved, for now, but my respect for Samsung may never return.