Defiant X: The U.S. Army's New Stealth Helicopter?

In jointly-released statements, Sikorsky and Boeing announced their Defiant X aircraft to the world. The advanced helicopter design is a contender for the Army’s Future Long Range Assault Aircraft, currently one of the Army’s highest priorities. Lockheed Martin, Sikorsky’s partner company and Boeing released their identical announcements simultaneously.
Their Defiant X design is based on the SB-1 Defiant, a similar though smaller technology demonstrator. In June, the SB-1 recorded a top speed of 235 miles per hour, already much faster than typical helicopter speeds. According to a SB-1 test pilot, the SB-1 used less than 50 percent of engine output to reach that speed, indicating that the larger and likely more powerful Defiant X could reach even higher speeds.