I was actually contemplating making a thread similar to your comment. I don't know what voodoo they did. But, my Zwave mesh is IMMENSELY better. (And my ring range extenders are actually getting used finally) Before the update, I had several multi-hop devices and they were hopping through EVERYTHING BUT the range extenders. More than 75% took at least one hop to the hub. After the update, I am down to ~40% that aren't directly speaking to the hub (and the ones that are go through my extenders primarily)
I did have some funny business with upgrading the generic Zigbee CT bulbs to advanced. But, all I had to do was configure, then set them again. (Funny business had been commented on before - Once you hit configure, they go to MAX CT and 20% set level)
Otherwise, everything is lightning fast for the past two days. (Which is funny, because coming from ST, I thought it was already lightning fast to begin with)