Always got to have someone throw in nVidia having superior drivers. It doesn't have to even be remotely accurate or on topic. How does nVidia offer support for Hackintosh? I'm sure Apple would be interested in this? They love companies making money off of their IP by circumventing them.
Nvidia, just like AMD, offers drivers that are delivered in OSX updates or at least in the case of Nvidia, also as a downloadable web driver. Both vendors have device IDs in their drivers for many GPU models that are not in any Apple computer. What I meant by support is that Nvidia GPUs and drivers are far more likely to work in non-Apple configurations.
The main difference comes from how non-Apple hardware combinations and bootloaders manage to get the GPU working. With AMD this has required anything from modded kernel extensions to having dongles in a particular display connector - weird and often complicated and half-working fixes. By comparison with Nvidia even the new GTX 980 is easy to get working with full 3D acceleration. If that isn't less hassle with drivers then I don't know what is.
Apple really doesn't care about people running Hackintoshes. They are few considering it takes educated hardware purchases and decent technical prowess to be able to do a fully working Hackintosh setup. Over the years Apple have done pretty close to nothing to disallow this.
By not including DP1.2a in their cards, isn't Nvidia pretty much dropping even the possibility of Adaptive-Sync support?