Well i decided to figure out just about how much more xp you get per kill, how much less you need to get, and how much more xp quests give.
Lets start with total XP you need to get.
On one of my alts, at 30 he had 48000 xp on the normal servers, on the PTR's he had 38000. Thats -10000! Just at level 30! So lets do the math, thats about 80% of the total normal experience right? I tested this with my friends character too, level 42. His xp was 80% too. So I'm guessing that it is 80% of the XP you needed before.
[IMG]file:///C:/Program%20Files/World%20of%20Warcraft/WoWTest/Screenshots/WoWScrnShot_111207_202630.jpg[/IMG]
^ The PTR'S XP
Now lets talk about XP gained per kill.
At level 30, my alt got 280 per kill, killing a level 30 mob. In the PTR's he got about 370. Well, 280/370 is also 80%. So that means that it increases 20% correct?
Well, time to talk about questing XP.
No doubt you've figured out by now that everything increases by 20%, or decreases by 20%. And guess what! This is the same! Experience has been increased by 20% per quest at any level.
And if you didn't know this, you get the xp bonuses at levels 20-60, and you get the quest bonuses at levels 30-60. Its why i chose my alt that was level 30.
Thanks for taking your time to read this! I hope this helps some wonderer's.
Also i am very sorry if this was posted before, i looked all over for it and saw nothing.