Originally Posted by
dpham00 The scaling feature... It really saves not very much battery... I wouldn't use it unless you absolutely need every last bit of juice
I suspect we don't really know how much battery it saves yet.
We can see estimates in some early videos. But, like everything, I bet it will depend on any number of factors, the biggest of which might be: How much screen on time from that point on would that user have? Also, the type of apps used with the screen on, such as screen intensive apps(heavy gaming, YouTube, video chats) drawing power are probably factors that will make the battery savings amount vary somewhat.