I have couple Korean Customized keyboards, they all feel great. I was always thinking it's because the lubing, tuning, special spring, plate, etc..
Yesterday, I put a vortex alu case on my stock QFR Red, and wow, it instantly feels much better. The main change I notice is that key stroking now feel more solid and the sound is more appealing too.
Although the quality of vortex is not that good, mainly because the bad painting job, it does make the typing feels better.
