I just did several dives in 69 degree water with a two piece T2 suit. It was warmer than my 3mm wetsuit, only issue I found was I should have gotten a size smaller lower. I was shore diving and when getting out of the water the pants seemed to drain slowly and I had sags filled with water. Solved the problem by putting boots under the pants. I also used a pair of hockey style suspenders to keep everything where it belonged, had zero issues with the top riding up.
Overall I love the Sharkskin, the front zipper is easy to use, it is easy to put on and take off. Turn it inside out and it drys quickly. It is also a lot easier to pack! I am selling my wetsuit!