I keep Old Lucid turned ON (and New Lucid OFF).
To my ears, the new mode sounds unnatural with most of the music to which I listen: like I'm always in a cathedral, except there's no echo. The old mode sounds more or less natural. For the last day or so, I've been using 4-pin XLR connector, but I thought old mode was the way to go with the single-ended connector as well. It seems like a few people who have recently received their Taboo 3 prefer the new mode though, so take that with a grain of salt.