For the grass geeks out there, what are your thoughts on applying this to an entire course in South Florida? It would replace a Tiff 419.
Why do you want to replace the grass? What's driving the decision?
Replacing all the grass on an existing course is a lot different than having to spec grass for a new course. For one thing, you've got history -- how the current grass is performing, water quality history, etc. For another, you don't have to replace it unless there is something really going wrong with the current grass.
Paspalum is the "in" grass especially where desalinated water or effluent water is being used, but it's far from the only grass that provides a great surface. Streamsong is actually 419 bermuda wall to wall, except for the greens.