A couple days ago we were talking about the barbarian xp penalty and I expressed uncertainity that it existed.
You win!
The test: Make a lvl 1 Warrior in Gloomingdeep. Do the tutorial NPC hail and kill the first kobold.
Results:
Wood Elf - Total gained: 95 Ticks
Half Elf - Total gained: 95 Ticks
Human - Total gained: 95 Ticks
Barbarian - Total gained: 91 Ticks (i.e. He took the 5% penalty)
Halfling - Total gained: 98 Ticks (i.e. She took the 5% bonus)
At that point EQ crapped out on me so I never got to test ogres and trolls but I'm sure their penalties bear out. Was curious about Vah Shir as well but if you really wanna know, go make one and see. If you're going to use my numbers, remember to make a Vah Shir warrior or rogue. Warriors and Rogues get a 5% bonus for their class so if you make a VS shaman and compare it to the Wood Elf warrior, your numbers will be completely screwed up.
For anyone wondering, supposively humans were supposed to get the 5% bonus for being mid-line with no special abilities. It was accidentally programmed into the halflings and no one ever bothered to fix it.
Regarding hybrids, this came up on the Live forums when someone tried to use this method to prove hybrids still carried an xp penalty. When SOE "fixed" the penalty, they did so by giving a bonus to mob xp when given to a hybrid. I don't know why they didn't fix it directly, probably for the same reason halflings still have a 5% bonus. Maybe it's harder than it sounds. Anyway, the first 75 ticks of xp came from hailing the quest NPC. Because of how the hybrid penalty was corrected, you'll still feel the xp penalty when hailing the NPC as it's quest xp not mob xp. During the usual course of the game this wouldn't matter unless you plan on levelling solely off Crushbone belts, etc but it does ***** up your "reading" when testing via the tutorial.