Yea, CM Quickfire Rapid keys get shiny rather quick. My space bar on the Quickfire held up worse than the spacebar on my Blackwidow. That's not to say it's not a great keyboard and all.
For what it's worth, I'm replacing my main 37 typing keys with PBT side printed, and the modifiers and the like will remain ABS until I find a full PBT set I want to invest in.