Only in very specific scenarios do I use AoE chakra state. Maybe 2 or 3 different boss phases in an entire instance. The primary reason is because holy word: sanctuary is, frankly, not very good. Even in a melee-heavy group, where sanctuary is always on 5+ targets, I find that it only does 5-8% of my healing for a fight. If I stay serenity chakra, renew is nearly always top healing, primarily because of the refresh, and HW:serenity is nearly always 10+% of my healing. Even in fights where raid damage is very high, serenity always significantly outperforms sanctuary.
The ability to insta-heal for a high amount AND refresh renew to maximum is just too good to pass up. In sanctuary chakra renew is prohibitively expensive. It's just not worth being cast, ever. At all. In the past, renew was buffed in sanctuary state. At this point I don't even think that would help, because HW:sanctuary is just so weak.
So, TL;DR: Sanctuary needs something that makes it more worthwhile during high raid damage, raid-not-stacked phases. The reduction in CoH cooldown and increase in CoH and PoH output (plus a weak aoe heal with a long CD) does not make up for the loss of HW:serenity and the ability to refresh renew with an insta-cast, cascade, or cheap heal. This makes me feel like the chakra states are severely unbalanced in favor of single targets.
I am aware that part of this is because I am in a 10 man group, and in 25's this is much less of an issue. However, I think it's quite bad in 10 mans and could still use some balancing.