Code Quick isn't quick, it's pretty silly. Actually, the U.S. Army Signal Corps used to use something very similar decades ago (many decades ago) and I witnessed this at Ft. Monmouth in the late 1960s. I thought it was really stupid then, and it didn't get any smarter over time. Any time you have to hear a character and then think what it reminds you of is a pretty big handicap; kind of like speaking a different language but thinking every word or sentence in English first, then translating it in your head. Not too quick, and it will never make you fluent. You're not fluent until you think in the language you're speaking. Same with Morse code, but Morse is so much easier, since there's only about 40 words in the whole language. Who the heck can't learn 40 new words?