HiDPI on Windows tends to be a nightmare due to the fractured GUI elements within the whole ecosystem. Between NTVDM, Win32, .NET and VB apps alone there are too many differences and inconsistencies to get HiDPI to work, on top of that, due to the 'backwards compatibility' they can't easily fix it. It's highly unlikely that they will break with their past like for example Apple did a few times(first with the motorola->PPC and then with PPC->x86 on top of the Carbon->Cocoa and Classic->Unix switches) .
I would argue that hidpi doesn't look as good as Mac, but better than Windows. I'm primarily committed to Gnome, so I cannot speak for other desktop platforms, but GTK applications look pretty good and the font rendering is fine (again, not great like Mac, but not bad like Windows).
But there's always that one tool that just isn't there...