I've owned 3 Senates, still have 2. Alloy was most forgiving, Graphite was most well rounded, Lithium was fast and least forgiving. Skiing is a mix of open water, and large public lake ski course. I ski the large public lake course 90% of the time, open water 10%. Lithium is awesome if conditions allow. If it gets windy or boat traffic the ski is too busy and my skiing suffers significantly. The graphite was by far the most well rounded, with a great balance of forgiveness and performance. The alloy was very forgiving. It was slow to react compared the graphite or lithium, but not in a bad way. I'm a 32mph 22-28'off skier.
FWIW I kept the Lithium and my wife skis the Graphite. Sold the Alloy.