A lot of people are complaining about putting this into CSS, but I think that people are forgetting that using null transform hacks[0] is already the status quo for making animated elements more performant.

What this property does is lets us continue doing the same thing, but in a way that the intent is clear ("I'm using this property to make the animation on this element more performant" vs. "I want to add a transform that does nothing"). Furthermore, it lets the browser decide if it wants to add any optimization, and it can decide which sort of optimization is best.

While it would be nice if we didn't have to do this hinting at all, the fact of the matter is that it's hard for the browser to predict what will happen on the page in the future, and we're already having to do this (just in the cryptic null transform way), so it's nice that the web platform is letting us do it in a standardized way that communicates our intent clearly.

[0]: http://aerotwist.com/blog/on-translate3d-and-layer-creation-...