In 1.x I knew of a few times (usually going THM instead of BLM) that you'd go with a class. When would that ever make sense in XIV ARR since you not only lose 5 skills, but huge chunks of HP / defense. I don't recall it being such a huge difference in 1.x playing as my class or job other than a lack of a few skills. I could just be getting old and forgetful though.