FoOrum

Stats
Soft caps of that stats are:
Strikethrough - 30%
Critical Hit Chance - 30%
Critical Hit Severity - 250% (300% is a hard cap)
Vigor - 30%
Armor Pierce - no (75% hard cap)
Multi Hit - 60%

Priority stats for DPS Spellslingers in descending order of importance are:
Critical Hit Chance,
Critical Hit Severity,
Vigor,
Armor Pierce,
Multi Hit.

Strikethrough
Strikethrough is a stat that only need to be increased to cap value:
GA - 11% without True Strike fusion, 9.5% with True Strike fusion rune
DS - 17% without True Strike fusion, 15.5% with True Strike fusion rune

Critical Hit Chance
Target values for Critical Hit Chance:
Dungeon - 16-17%
GA - 20-21%
DS - 24-25%

Critical Hit Severity
Target values for Critical Hit Severity:
Dungeon - 190-200%
GA - 200-210%
DS - 210-220%

Vigor
Target values for Vigor:
Dungeon - 3-4%
GA - 11-12%
DS - 14-15%