After a long testing, the Ryujinx Nintendo Switch emulator has officially added the Vulkan backend to its main build.
As the emulator's developers explained, Vulkan is a no-brainer for Intel and AMD users, while NVIDIA users may want to decide on a game-by-game basis against OpenGL.
First of all, you need to know that any shader caches you've cultivated over the years will sadly cease to exist once you update beyond version 1.1.200 and boot a game. While this does mean that you will start from scratch in every title, they should be much quicker and less painful to rebuild thanks to SPIR-V's compile speed! Should you choose to use Vulkan.
Other than this... not much. AMD and Intel users will want to immediately set Vulkan as their backend and never look back while Nvidia users have the luxury of choice. While in most cases Vulkan will likely be the better pick due to its lower shader stutter, there may be some games that render/perform better in one or the other, so the world truly is your oyster. Shaders built for one backend will rebuild into the complimentary set for the other when you switch, so nothing is lost by trying both. A good strategy may be to undergo the initial stutter with Vulkan and then switch to OpenGL if it performs a little better. Your choice.
As you can see below, performance gains with Ryujinx's implementation of Vulkan can be incredibly significant on AMD hardware. Super Mario Odyssey gets an astounding 413% frame rate boost, while Mario Kart 8 Deluxe is 163% faster.
That said, there is a caveat you should know about enabling Vulkan in Ryujinx: VRAM usage will get higher. To counter this issue, the developers have added a feature called Texture Recompression, now available in the graphics tab. This will slightly decrease texture quality but should prevent any unwanted driver crashes. The Ryujinx team recommends enabling Texture Recompression for GPUs with less than 4GB of VRAM.
Lastly, a few Nintendo Switch games like The Witcher 3: Wild Hunt and the recent release Xenoblade Chronicles 3 don't boot yet on AMD hardware with Vulkan enabled.