N64 emulation isnt perfect on pc either and with a 733mhz processer and 64mb of ram in the xbox you cant expect much better.as for the snes emus,i only had slowdown with the earlier releases of some snes emus,with zsnexbox3.3 cant say ive ever had any slowdown and thats with running certain games with filters. whats wrong with mame on xbox? anyway back on topic you are right about the emus on xbox gav. maybe someday it will happen.