As to the Retroarch MAME I always had little niggling issues with it with regards to controls (but I'm in the minority there), so I stick to the standalone. I personally use Retroarch for everything except, Dolphin, MAME, Demul, and PCSX2. Those last 2 are not in Retroarch period so you have to use the standalones there. MAME is a personal preference thing, and Dolphin is superior as a standalone. If the PPSSPP Retroarch "has" been updated that may be OK also, I know there was talk of bringing it inline with the standalone, but I haven't used it since then.