Could you guys pay some attention to Gambatte? Nobody mentions it, but the 3DS is in a dire need of a perfect GBC emulator. Gambatte is already pretty much perfect, but the sound is really bad on it, a lot of notes get "scratchy" output. Try Mario Tennis out for example, it's terrible.
Thanks for your hard work as always, libretro devs. You've doing a great service to the emulation scene, not just on 3DS.
You have to understand how difficult what you're asking is. How difficult it is to code to a specific platform.
Libretro devs have a ton of platforms to mantain. Vita, Windows, Linux, Android, Xbox, you name it. They have several cores, ranging from NES to PSP. With SNES9X 3DS you can already see how much time was invested into optimizing A SINGLE CORE for the 3DS. Now why should libretro devs invest so much time into optimizing JUST for the 3DS when they have to mantain their codebase for several platforms? Why should the 3DS be privileged by them? It's not how it works.
A lot of the cores work really, really well on the O3DS. I'm already thankful for them.