Swords can't bleed, so why taste for blood?
Use a nail bomb, ripper's glove, or put on bladed metal armor in some fights that don't require mobility.
I'd definitely drop survival insticts for more agi or strength and make a build that's quite different than the one I currently have though.
Those 6 points invested in CON for survival instincts give more total damage rather than if you had invested them into STR, but with the consequences of less melee skill and dying from a stiff breeze. Evasive Maneuvers sounds good in it's place, or Blitz.
Here are some calculations with the claymore, level 25, 11 base STR, rathound regalia, recklessness, focus stim, 7 dex and the base from the sword itself gives me 60% crit with SI, 375% bonus(2 critical power specs) so the total damage if it's a crit is 475%.
45-135 base damage, 90 average on non-crits, 90*4.75=427.5 on crits. (90*0.4+427.5*0.6)=292.5 average damage per hit
Now i'll edit my stats to have 16 base STR but do the same calculation without +30% SI crit
56-169 base, 112.5 avg non-crits, 534.375 crits. (112.5*0.7+534.375*0.3)=239.0625 average damage per hit
That is a 22% damage boost(18% on straight super steel) which might vary depending on your level or other factors(probably more on other high-crit uniques, i don't want to pollute the thread even more with mathematics).
Fighting normally and getting hit just enough to reach the threshold without dying is annoying, better to start 99% of fights while under 30% without getting hit in the first place.