I just did a lot of research on it, and while it's small and can support 15khz through VGA or SCART with the proper add-on (I wouldn't bother with composite), I'm not convinced the experience would be as good as GroovyMAME. According to
this gentleman, the audio lags slightly, and according to him,
here, and
here, refresh rate has to be set for each individual game, which I believe requires a reboot. And it's weaker hardware, so more recent arcade games might struggle to run.
I'm tempted to try it because it's so portable, but GroovyMAME with CRT Emudriver would deliver a superior experience. I'd like to hear opinions from people who have tried both setups. Namely, what are all the limitations of using a Raspberry Pi on your CRT instead of GroovyMAME?