Depends.

Fist Spec is a static +5% crit. Which ups white damage by 5% and yellow by 5.15% (from lethality). The issue is it's mitigated by defense and resilience. So for fights against targets with high values for those two stats the bonus gained is significantly less.

Sword Spec is a bit harder to calculate as the damage isn't exactly the same based on what type of attack procs it (as opposed to +crit which without mitigation simply doubles damage dealt). ie. A MH white damage hit will proc another MH hit which is effectively the same as +crit. The difference though is that an OH hit or yellow damage hit will proc a MH hit (IIRC). In the case of an OH weapon this will be more damage than what you'd get from +crit (in most cases, requires that your MH hits harder than your OH but if you're a sword/fist spec that should be the case), but in the yellow damage case it will be less. Also it resets your MH's auto-attack timer so it's even messier to calculate.

Also remember some buffs proc per hit or per crit (judgement of light, imp leader of the pack) so depending on the group you're in that may increase one's usefulness over the other.