I'm wondering if Gauss Barrel is actually worth using, outside of decent AoE fights, at all. You're losing all your Auto Attacks, get a cast time on 3 of your GCDs (which could lead up to a dps loss when having to dodge/move) and turns Rapid Fire from a Haste-like buff into just removing your cast time. In return you only get a 200 and a 100 (+300 AoE) potency attack unlocked by it, which seem both rather lackluster compared to what bard gets from using Wanderer's Minuet.