I've got one and it runs some A500 games just fine, some not.
There is a database of people's experiences in running games here:
List of compatibilityBTW the 275Mhz version is just those standard ones that overclock well, no new components or anything. My standard GP2X overclocks to 250 no worries, never tried faster.
There has been a few big developments (memory access, second CPU etc) in recent time so I wouldn't look to youtube videos as any sort of guide unless they are very recent.
