Symptoms, gender, how you behaved (did you relax on what you ate/drank).
I will start. So far, my nausea has kicked in much earlier than my first, the tiredness is less so far, and the biggest difference is my boobs! Last time they were so sore and ballooned, became bigger than my head and couldn't find bras or outfits. This time they're normal so far and I am delighted.