In crucible half of glaive shots do 0 damage even though they are obvious hits and give shield energy, and the damage goes through only if you hit another shot. Then the other half of your shots hit and do damage, but don't give shield energy. And the melee registration is even worse. This seriously holds them back from being usable and I haven't seen even a mention of it in any known issues yet, though I might have just missed it if so.