RE: Bad Pushing Problem(w/ hyper PCR)
Thinner fluid means less resistance, and that means the diff will be more likely to naturally spin the easiest end. That means that you won't break the outside front tire loose as easily since weight will shift outward, (instead power will go more to the inside front tire) giving you more front traction under power. Thinner center diff oil means that it will send more power to the front under acceleration (since weight will shift rearward), but thicker rear fluid means that what power does go to the rear will be divided more evenly, causing both wheels to break loose easier, giving you the ability to slide the rear end around.
My buddy runs 5k/10k/10k in his Hyper PCR and it works well for him. I think its too tail happy, but he likes it.