Originally Posted by
Yxiomel
That's not always true - Conc is a 33% DPS boost to only the DoT part of Sigil, whereas Quickened is a 25% boost to ALL of sigil. Since nearly half the damage from sigil is in the initial burst, this makes Conc only worth about 17%. The only other consideration without Flame Crash is the extra global to drop the exta sigil when using Quickened, which will drop 1 shear every 2 minutes; this is significant in single target, but not in AoE.
Thus, Conc is better with Flame Crash (owing to all those extra sigils unaffected by Quickened) and probably single target (requires comparison of fire mitigation vs armour). Quickened is better AoE if you don't have Crash (although that might be considered a weird situation).