As plain as the nose...
Where? This site sir, click on the VAF logo on the top of the page. Look below the challenge coin story, there is a picture of an RV4 with the Hartzell Composite 2 blade on an RV4, add a blade and you have an IO-540 prop, or a Cirrus prop for a small fee.
Being a Rocket driver, none have challenged the good old Hartzell 2 blade paddle "J twist" in overall performance yet. It's heavy, has a 6" extension for the Rocket cowl which restricts it to 3.5 G's but works great. When they offer composite blades for $5K, I'll consider it...
Smokey
HR2