I just started testing PDK with a +1 heart to full Warlock. Charisma Bastard swords.
IT IS AMAZING. The 3d6 Light Damage scales with Spellpower and ALSO procs fully on glancing blows. Thank you for this.
You are absolutely correct. However, after testing warlocks a bit more, it turns out that the 3d6 light damage is awesome. See above.
As such, our DPS comparison is
Bastard Sword vs Khopesh
5d10 vs 5d8 (~5% in favor of Bastard Sword)
17-20/x2 vs 17-20x3 (17% in favor of Khopesh)
20% damage glancing blows with 30-50 light damage bonus (10-20% in favor of Bastard Sword)
Additionally, this frees up some otherwise wasted points in harper, which I am veryr happy with.