I would like to say that while hammer of sol lasts longer without doing anything, it loses time every throw. With the forge master perk on it decreases that reduction but not by too much. GG however has those 11 seconds regardless of wether or not they choose to fire at all. Firing all 4 GG shots (with acliophage) it still takes the same amount of time. Would you rather sunbreaker a had a set amount of hammers to throw or they can run out quicker if they miss, unlike GG.