Sara Soueidan lets us know
translateZ(0); is out and
will-change: transform; (et al) is in. The general tips being: use sparingly, apply before you need it, be honest about what really needs it.
There is some backlash about this, mostly centered around the idea that browsers should be handling this for us. The opposition saying it's too hard for browsers to know, so this is essentially browsers and devs meeting in the middle. Sounds a lot like the responsive images debate, doesn't it?