Watch out for the emulator.cfg file in there as you would not want to overwrite one if you have one.
I prefer AdvMess over CoolCV as the video takes up more of the screen and it bypasses the title screen. Both controllers can be configured. I made a small modification to AdvMess to fix the controllers. I have also tested Odyssey, Bally Astrocade, 5200 (keypad works), and other consoles. Performance is great on a PI2. I have not tested it on a PI1. Below is the entry I have for the es_systems.cfg.
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