i can tell you that there are some improvements with 5.1ce and if you use the ini file you will have all the best settings as far as i remember you do get some improvements with n64 emulation but you have to remember surreall is optimised for a stock xbox with a 733mhz processer and 64mb of ram as for other emulators i dont really think it would make much difference and that includes mame. as for you mentioning the x68000 emulator that already runs full speed,what to do is in the options screen when you select a game set the speed to 16mhz,this overclocks the x68000 cpu and you will see a difference if you think some games are slow.