First of all, sorry for my bad english !
I think I "discovered" something. At least after searching a lot @ google I couldnt find anybody talking about it.
Heres the story:
I started leveling an undead warrior and as we all know, leveling a warrior is horrible in terms of self healing. I skilled first aid and healed myself sometimes but not too often. I got to lvl 10 when a friend of mine started playing alliance and I switched to playing a dwarfen warrior and started again. From lvl 6-8 I noticed that it was much harder to gain full health after every mob even with first aid and eating. Something felt different so I checked my hp regeneration ticks. My dwarf @ lvl 8 with 21 spirit ticked for 3health every 2 seconds. I logged on to my undead warrior and he gained 15health/tick. (lvl 10/28 spirit). This means that my dwarf regenerates 15health and my UD 75 health in 10 seconds (5 ticks). I searched the whole web for the exact formula for hp regeneration in vanilla but I couldnt find anything useful. I seemed very strange that a difference of only 7 spirit points gave 5times the hp regeneration. I couldnt find anything so I just tried to play on and the next mob dropped a scroll of spirit whigh gave my dwarf 3 spirit points and now i was ticking for 7 health. Only 3 spirit points doubled my regeneration. Soon after that I gained a level and now @ lvl 9 I still had 21 spirit and I was still ticking for 3 health (scroll expired again).
So why do I tell you all this? I think the racial starting stats make a huge difference (at least for the warrior!) UD starts with 25 spirit and gaining 5 times the health between mobs is remarkable. (considering that you have ~ 250hp @ lvl 10 gaining almost 30% of your health in 10 secs) makes it much easier to regain health between fights.
Does anybody have the exact formula for this?