An experience bonus is definitely a plus when it’s a trait, since it means that the recruit gains power at an increased rate compared to other recruits. More power means more survivability, so conversely a exp penalty means that your recruit has a lower chance of survival than a recruit with an exp bonus. It also means that said recruit will catch up quickly to your higher levelled mercenaries when you recruit him as a replacement, making him more valuable than those who’ll take longer. I still don’t like the perk version, but it’s rather valuable as a trait.
