In PvP yes they can mean the difference between dying horribly and winning.

Outside PvP they are very minor. Long as you don't want to top any leader boards 12% bonus health or extra mana or stamina probably wont make or break a character.

However if you want your racial to seem much better just look at Argonian's they get to swim faster and that's about it there is no class or end game content that is at all helpful for.