If you max lvl Force Blaster and Soul Breaker, Soul Breaker will always have more power. For example on lvl 52 Force Blaster 929 power add to p.atack and Soul Breaker 1051 add to p.atack. I did some tests with it like with soulshots, no soulshots, with momentum charges and without. Looks like the Force Blaster dmg is always higher than Soul Breaker, which makes no sense. I would agree if Blaster with charges do comparable dmg to Breaker but it do a lot more dmg even with 0 charges. That means some important mechanizms are not in description or its a bug.