Good sound, weak mic, loud beeps
I replaced my 520s with the 600 v2 set. Rather than speaking this set just beeps, which while being an improvement on the nasal American voice is less helpful at times since there's no list of what the beeps mean. Speaking of beeps, you also need to ensure you're not wearing them when you turn them on or you'll go deaf. They also seem to need charging sooner than the old ones. The sound is good, the microphone is a bit weak - it doesn't pick up well being tucked away at the side.