Flashbios is legal bios so if you get it from xecuter or xbins, they most likely are the same. On the other hand, if you are talking about hacked bios released by xecuter, then the difference is hacked bios is illegal bios which is designed to get the full potential of X3.
Main function of flashbios is just to flash your chip to other bioses, including hacked bioses. It does nothing else besides lock and unlock hd.