All in all, I find CB to be significantly more useful than PC. I can just run past mooks while casting CB at them and continue on to the next spawn, leaving most, if not all, to die long before they catch up to me. Even from a relatively short distance (say 10 yards), I can cast just two at a couple of archers and they will be dead before I can close to PC range. Couple this with the fact that you can continue to deal damage even while switching to other songs, the fact that encore always activates from kills, and the fact that Long Solo increases its duration, and it's no wonder why I prefer CB. That's not to say I don't like PC; I love PC. I just can not use it nearly as effectively without starving myself of mana.
You find CB more effective because that's what you know how to play and at the difficulty and ranges you play at. You don't know how to maximize PC.
What difficulty are you playing, and what maps? Sounds like old maps and threatening or below from what you describe, because you wouldn't be able to pull running past enemy archers/horrors/despair demons off in FC without a lot cunning, knight music, and willpower against the ranged physical and magic attacks on Perilous Castle. If you're able to pull perilous FC, please do share video and demonstrate for everyone how you do it, as that'd only help everyone involved.
I've used CB to kite just as you've described too, but enemies don't die as fast as you describe on perilous. On old maps and threatening and below, I just fast beats and PC through everything because they're dead from the first PC (or second), and it triggers encore. There is some skill involved in when to PC, maximizing PC's AoE via positioning yourself and enemies into clusters of course. It won't matter if encore only triggers half or even 1/4 as you say, if you're hitting 12 targets at once (or even four, considering your supposed 1/4th). Again, we can't disprove each other's platforms, since we are different platforms, but we can demonstrate what happens on each other's platforms.
Re: Effective ranges and # of targets for CB vs PC
What you've done is described the optimum and near optimum distances and usages for CB. i.e. few enemies, long distances. At 10 yards you should be taking cover on Perilous vs archers. At 2 enemies and long distance, (10 meters is outside of strike range, and outside of attack within 2 second range vs archers).
Basically, you're doing it wrong with PC. You need to maximize cover and clustering of enemies. 2 and below is pushing it for PC efficiency unless the enemy is small like a Deepstalker. I cannot prove what happens on an xb1 since I don't own one, but I can show what happens on PC.
I can provide more video of course, but I already have video of myself using PC (although not as well as I do it now).
http://forum.bioware...t-dragon/page-3