If you look at the OP's armory, you will see that the hunter has over 37% crit unbuffed. Although it can be improved a little, that is more than sufficient at this point and is actually more than Fen's 36.65%.
Our points are:
- That there are actual reasons for PS to fall off other than not having enough crit rate. It is the nature of RNG and movement heavy fights. For example, assuming a buffed 50% crit rate, even during a perfect standstill ideal DPS case, you can only do 5 specials during the 8s before PS expires. If all 5 are Chimera Shot, Aimed Shot, or Steady Shot, you still have a 3.125% chance that you will not get another crit over that time. What is more likely is that one of those 5 shots is an Arcane Shot, meaning that with only 4 PS proc attempts, there is a 6.25% chance that PS will drop off. Now add in the movement/stun/interrupt element with missed special opportunities, and there is even a greater chance that PS drops off.
- If it falls off, there really is no penalty. There is no reason to go out of your way to try to keep it on the target.
Telling someone who already has over 37% crit that they need to add more crit because their PS is falling off once in a while is just bad advice. Crit is worth less than Agi and AP. As such, he would be better served to add more AP than crit so that everytime he crits at his current crit rate he does more damage from the crit (including the PS effect). And even better than that would be to add agi for more of both crit and AP.
I understand the points raised and agree with your two bullet points (very nice analysis on the first bullet point). I am not sure I agree with your comment that its bad advice to recommend that someone with 37% crit add more. According to the spreadsheet (using my gear profile as an example) one addtional point of Crit equals a gain of 1.134 dps while adding one point of AP only nets a gain of 0.627 dps. Agility is still king with one point adding 1.427 dps.
Edit: Adding caveat that stacking one stat to the exclusion of all others is typically not recommended and I am not recommending crit stacking.
Edit2: Thanks to Galushi for pointing out the flaw in my reasoning.