Lutecris I second this.
Ran into two things tonight that others have mentioned, adding my experience.
With only one or two songs in my Measure, casting a detrimental song still dropped a beneficial one. Doozle90, Timotron and rogue163 all saw the same. I get the reasoning from Xilith's post, that 3 or 4 songs plus unlimited detrimental ones would be too strong. But that only applies at capacity. With a free slot, casting a mez or DoT isn't exceeding any limit, so dropping a buff there is a cost with no balance purpose. A free slot should let me swap detrimental songs without losing a buff.
Second, with mez sustained on one target, clicking it again for the next target cancelled the first mez instead of casting. So in a bad pull, the button that should lock down mob two unlocks mob one, and I need a second press to actually cast. Opposite of what I'd expect in the moment it matters most.
If that's all intended, fine. But reading the deep dive I pictured something simpler: twist like always, and the last 3 or 4 songs you played keep going. Full Measure, oldest drops. Easy to predict, and it keeps the same cap.
The rest of the rework feels great. Just want the part I press every few seconds to be as predictable as everything else.