Flat plane crank

Flat crank makes it a little easier to plumb a well scavenging exhaust that works up high. Especially with variable cam timing.

Yet it has balance issues and the valve train will never know what kind of crank lives beneath it, and so must be up to the task anyway...

As a result, a flat crank sounds different/neat, makes for a marketing buzzword, but isn't something worth investing in for performance unless it's in an entirely new engine. Especially for a crowd that tends to do most of their work under 7500rpm (and many of us at half of THAT).

Drool all you want over it, but few of us will be missing anything special.