Swords do have a decent crit rate, but not a good one. Blunts pretty much abandon crits for higher accuracy.
With a bow or dagger my DE has 145 crit and is pretty much guaranteed to get at least one critical hit every battle, which means a lot since mobs don't live through too many arrows.
With a sword equipped my other DE has 91 crit and there's a huge difference in the frequency of crits. Granted he is lacking a few +dex tattoos, but that shouldn't make a difference of more than a few points.
Adding a focus SA to a sword generally puts it at a higher crit rate than daggers or bows, combined with buffs it guarantees frequent crits.
Critical damage adds a few hundred p. attack whenever a crit occurs (going higher as swords increase in level). Though the difference in damage is quite noticable, I'd say that overall damage output is higher with Focus, especially when you have that critical damage being covered by a buff.
I guess its on prefence :P would you like to crit more or crit more often?? :P I prefer focus myself. But the difference in the 2 SA is 200-300 in damage during a crit.
focus is the PvE SA. W/ so many multipliers - focus is times better (DW, fire dance, CoV, Kitty buffs, Boss Jewels..). This is why DE rogues are gimped pve: no focus passive (unbuffed - i have 261 (no tats: just doom, in PL 256) crit rate w/ kris).
Crit dmg is plain pattack added on criticals and it's good for daggers only since stabs are not affected by critical rate. Even VS alone makes focus better than crit. dmg.
The only one exception are TH/PWs w/ Focus,SoH and kitty buffs they can hit the limit w/o the focus SA itself but that's a bit too rare to consider.