Overkill means running every game at monitors maximum refresh rate with all settings highest 16AF and 8xAA.
In Crysis I only get around 45-55fps constant.
"Only" 45-55 fps in Crysis with everything maxed??? My god, you need an upgrade!
Overkill to me means you will see very little benefit from spending more, and is probably closer to how most people would use the phrase rather than your "you literally will not see any benefit at all in any situation from something better."