I personally disagree with a lot of this sentiment. Retroarch is good for a last measure, but it's slow to initially boot into each game, and isn't the most user friendly experience. If you instead use forwarders for the vWii emulators like VBAGX, FCEUGX, SNES9XGX, Genplus GX, etc. etc. You get emulators that load each game considerably faster, output in the same quality considering these games were never made for HD anyway, and if you install them properly, you still get all the great benefits of the Wii U: pro controller support, gamepad support, etc. etc. And I say this as a man that still uses Retroarch on my Wii U when I need to, like it's the best option for playing Atari, Virtual Boy, Mame, etc. on the Wii U, not to mention the ability to emulate 2 Game Boys at the same time, but I would absolutely recommend those vWii forwarders (if you get the right ones) on the Wii U over using retroarch for all emulation needs.