U.S. military slang used as a superlative with roughly the same meaning as "cool" or "kick-ass", but cool in a special military sort of way. Sometimes expanded to "high speed, low drag". It can be used to describe just about anything connected to the military. It is typically not used when describing civilian objects (eg. the new Porsche 911 model would not be described as high speed, no matter how fast it goes). It has nothing to do with the actual speed of the object being praised, for instance the F-117 stealth fighter, because of its advanced capabilities, would be considered more high speed than an F-16 fighter, even though the latter flies twice as fast. Some things that might be described as high speed include new, advanced weapons, a particularly professional soldier, an elite unit such as the U.S. Army Rangers of Navy SEALs, a nicely executed high and tight haircut, or even a pair of unusually shiny jump boots. Typical usage might include phrases like:

"Did you see all those medals? That guy is high speed."

"We're getting some of those new, high speed night vision goggles in tomorrow, I can't wait to try 'em out."

"Those boots are high speed, man. How did you get 'em to shine like that?"