Hi Fergusolp
the sabertooth is designed more for overclockers and the IV Hero is an ROG board (will still overclock well, but not quite as well as the sabertooth), aimed a bit more at gamers. Both will give pretty much identical performance so personally, i'd go for the one you can pick up cheapest. they are both really good boards. for your reference, here is the official comparison:
http://promos.asus.com/us/z87/comparison/
Regards