I chose the James Cowl & Plenum for looks and expected improvement in speed & cooling performance. I really like the concept of controlling the pressurized space above and around the cylinders vs. the relatively un-specific space created by sealing the engine baffles to the top of the cowl. I also appreciate not stressing the cowl structure with ram air but rather controlling in the plenum.

Unfortunately the Plenum and Cowl do not align well at all and significant modifications to the interface are required.