Does anyone out there have any experience installing Hardie panel (the stucco variety) over ICF? This product comes in 4x8, 4x9, or 4x10 sheets. I am thinking of using battens to create a tudor look. Would it be best practice to install furring strips for a vented rain screen approach?

I would say yes to the batten strips for a vented rain screen. I'm sure that other posters here will disagree, and I know that the ICF mfg. would disagree. But I don't like the possibility of moisture buildup in my walls, so the rain screen is a plus for me. I also like to use tyvek (or eq.) under the battens. Just another layer of protection, that some will say is unnecessary, but that's OK by me.

I tend to agree. My concern is with the Hardie panel not being able to dry out possibly shortening the life of the paint and or the product. Using a water resistive barrier and proper flashing should ensure that any water that finds its way behind the siding cant find its way inside the home possibly through the joints in the blocks.