I had the pleasure of attending a show by Penn and Teller once. Part of the show involved Teller having his body separated into several boxes. Each part seeming to remain separate and still interact with Penn who was disassembling his partner. That was impressive enough but then they showed you how Teller did it, exiting the stack of boxes through a trapdoor in the stage and crawling on his back between each box to stick his head, foot and foot through to create the illusion. Here, watch it:
Really Teller's level of dexterity and flexibility is amazing. Not oh gee lookie that amazing. Scary amazing.
A few years later I'm in an rp playing Wildcat, an aged and ageless super hero who started in the 40's and was essentially a buff guy in a cat suit. Doesn't sound like a super hero. People argue whether Batman should be called a super hero because he doesn't 'do' anything. Wildcat doesn't even have a utility belt or stellar reasoning ability.
Recently in character Wildcat explained to a younger hero starting out (also no super abilties - one of Bruce's interns) that indeed they were super heroes. His reasoning? He defined a super power as when you can do something that most other people can't.
Doing backflips and pounding the snot out of people from mid-air definitely is the kind of skill I had in mind. So does Batman's trick of knowing where you're going to look, moving slightly out of vision and then moving back when you look somewhere else and a few thousand other tricks he mastered when most teen boys were playing video games and indulging in autoerotic activities.
Superhuman (Or nearly so) Dexterity
As with strength superhuman dexterity has three levels.
Low: (still within human levels but eerily graceful. Think Priss the replicant from Bladerunner). The character gets an advantage die when making ranged attacks or any other feat requiring motor control like stealth. On a roll of 1-2 the character's ranged attacks do maximum damage. The character gets a -2 to saves vs. long burst fire and other area attacks.
Paranormal: (not within human limits, Think River Tam from Firefly). The character gets an advantage die when making ranged attacks or any other feat requiring motor control like stealth. On a roll of 1 to 3 the character's ranged attacks do double maximum damage. The character gets a -5 to saves vs. long burst fire and other area attacks.