If I was replacing the mainsheet blocks on a boat that size I'd definitely get a Hexaratchet block. I sail often sail with a retired friend who was badly injured in a car wreck. His legs and hip were messed up and when the boat heels over hard it is rough on him. I convinced him to give the hexaratchet a try and he loves it. He can hold the load on the main comfortably with one hand and dump it if needed. It has enabled him to sail more often with less worry. I had one on a Hunter 27 and felt the same way about it.
Gary H. Lucas