What I found useful is to actually cast chain lightning once and see if it crits, if it crits, it really helps party kill a group of monsters but if it doesn't -> back to CC.
After this nerf, this one cast is never worth the sp so it's only CC. You have better luck being useful with prismatic spray than with any other offensive spell against monsters with a lot of hp. Caster DPS needed a boost, not a nerf. Sorcerer was already very weak when compared to wizard because of prestiges that fits current state of DDO.. This hurts them even more.
I like this 'count crit for each tick' for DoT spells like firewall and ice storm but it's not really a way to go with insta-damage spells.
You have trained yourself with fire. You cast a fireball. You got it just right and it burns a bit more than usual. <- Sounds logical but how is only one monster getting the real burn logical?