If you seriously want to play MAME games, use Retroarch with the latest MAME cores. MAME4DROID and MAME4DROID Reloaded are way too outdated and it's very hard to find suitable ROMS for these emulators nowadays.
Retroarch also has a more updated FinalBurnAlpha core which is the best option if you want to play CPS2/3 games, it seems to be the fastest for these platforms.
Search for Retroarch's Nightlies builds since the Playstore version is old and won't work with the latest MAME cores. It has its learning curve on how to use but it's worth learning!
One more thing: update your firmware to the latest LegacyROM 1.8Ghz (thanks Skelter
), you are going to need it to play most part of the games at a decent speed. Good Luck!