@shinki
Sven_the_Demon is right. Fighting a certain type of monsters has absolutely zero to do with how much your stats go up. Each class just has a certain stat growth for every stat. The higher the growth the bigger the chance to get that stat going up when u lvl up.
@Twannes93
Not true ;)
Necro actually is fastest till 50, but soldier is slowest.
After that on avg theres a minimal difference between Thief/Monk/Archer/Priest