As has been said, gamewise there's not much between them. Daily powers are nothing to base your choice on. It just comes down to preference.

Redguards - Extremely skilled warriors, largely known to be adventurers rather than rank and file soldiers.
Orcs - Extremely large and powerful warriors, partially ununified as of late, known to range from wandering mercenaries to honourbound soldiers.

I guess it just comes down to an aesthetic preferance.

Lol I just found the IDs for the racial abilities thanks to UESP wiki - finally I have a Nord Dragon-hunter with histskin and berserker rage! muahahaha.

..No need to play as an ugly-ass Orc

Redguard because everyone calls me "Redguard". Which is cooler than "orcs", who happen to be the only ones rude enough to call me "Milk Drinker". I hate orcs.