The value of stamina was doubled in 1.8 making it the most valuable stat. For example before 1.8 a stamina mod of around 250 stamina would give you around 3500 health, after 1.8 its 7000 health. Stamina value was a little low before 1.8 but 100% increase wasnt the right thing to do in my mind, 50% increase would have been just fine.