Drysuit for me in anything under 72. I will dive a 5 mil with a 2 mil core warmer down to 68 but it better be a hot day and no more than 2 hour long dives. The drysuit is so much wamer and the learning curve is not that big with a good mentor or instructor. And I don't find a drysuit harder to gear up in. In fact it's easier for me. No pulling and tugging a wet suit over wet or dry skin, slips right on and off, and with a self donning option don't need anyone to zip me up. And best of all after the dives I dry my hair or on warmer days let the sun dry it, slip the suit off, and drive home in my undies warm and DRY!