In the world of arcade emulation, the MAME 2003-Plus Reference: Full Non-Merged Romset is widely considered the "gold standard" for performance-oriented setups like the Raspberry Pi or mobile devices. What is MAME 2003-Plus?
Version Matching: Ensure your ROMs match the MAME 2003-Plus core version; using standard MAME 0.78 sets will work for ~95% of games, but you'll miss out on the "Plus" additions and bugfixes. mame 2003-plus reference: full non-merged romsets
Pitfall 4: Input lag on a Raspberry Pi.