The only stat that counts in the acc. slot is enhanced effect.
But lets see anyway..
Critical Strike:
- A critical strike is a base x2 of your damage, ignoring the opponents defense (absorb)
- The actual modifier is based upon a base of x2 + dexterity modifiers.
Critical Flux
- Gives you a % chance to ignore target dexterity when you score a critical strike. This works like Mind Numb, only for physical damage critical strikes.
Considering all that, I would assume +crit strike (the actual stat on an item) increases the chance of a crit. The other option is it increases the damage of a crit, but I see that as unlikely because it would just be a similar version of dex.
"How does it effect hit damage etc?"
The more crits, the more damage. I'm not sure if it would be very much though.