The "support" currently in Gnome3 is ridiculous: you can scale your fonts, but all the window decorations, panel icons etc remain tiny, no matter how you scale that. And you can scale windows by integer numbers which means you end up with window decorations being too tiny or too large because what you really would need is 1.45.
On top of that, none of this happens automatically, your have to use the gnome-tweak-tool to fiddle with it.
I do not know if you have actually tried to use Gnome3 on a HiDPI laptop, it simply is a terrible experience. Granted, not all of it is due to Gnome3, since the underlying abstraction model is totally broken and individual apps, including Java apps, are still doing their thing based on physical pixels.
It is breath-taking that such a basic aspect of interacting with an OS is still broken so badly in the year 2015 (and I hear it is nearly equally broken in Windows).
Cinnamon does a much better job about handling HiDPI right out of the box at the moment.
I have to admit I do not know how Wayland is going to address this issue, if it helps to solve the current situation I am all for it.
But that was not even my major point: what really annoys me about Gnome3 is the way how they without any apparent need took away ways of interaction, ways to configure and personalize, ways of how to get work done efficiently from their users and forced their one golden path to happiness on everyone.
As if people would be using Linux because they love others to limit their options and make decisions about how to do their work for them!