I learned with a straight key but eventually moved on to a semi-automatic key (bug) and later a paddle. The ‘bug’ was my least favorite. No longer use CW for anything. (Grammar Pedants: have ...

Instead of using mechanical paddles, [Sebastian] brought his iambic key into the 21st century by using a touch sensor. An ATtiny45 measures the time it takes for a single metal plate to fully charge.