Most nVidia GPUs suffer from under-development on closed-source VDPAU so even if the card is vastly superior in mathematical compute capabilities it may not necessarily be any better than the Intel GPU which is still capable of hardware accelerating the same range of media. Kodi is not a complex OpenGL app, so it doesn't really need or benefit from high-end GPUs.
Perfect, this is what I was trying to discover. I know the GPU is technically much more powerful, but is it even worth bothering with the Intel igp. I couldn't find a direct answer on if the Intel could handle 264/265, 1080p/60, 4k/30 or 4k/60 with hardware decoding.