I'm still playing around with the new build, but I have this really bad slowdown that seems to only occur after I load my game. This is like 100% guaranteed to happen if I save before a hard fight and load 3-4 times before I get it. Not only that, the slowdown remains until I quit the game. There is no way to simply reload. It's also pretty severe, as though things are moving in slow motion. I don't believe I got it before this update.

Also note this is different from the lategame slowdown many people have reported. I sometimes get that too, but this is more severe and is occuring as early as turn 10.