I am running a bladestorm melee build that focuses on maxing crit.

Should I focus on upgrades to damage based on sheet damage or are there situations where the sheet damage may misguide? For example sometimes items with a secondary stat (agility) seem to raise my damage over items with primary stat (ferocity) + crit chance affixes. Does the sheet damage take the crit chance into account and can I simply focus on sheet damage to make my upgrade decisions?