Neckpeice

Using the following TP Set:

http://www.ffxiah.com/item-sets/177431

Kannagi/Kamome
Red curry buns
/war (assume zerk is on)

RR/GH/Apoc

will Agasaya's or Iga neck win?

how about the same setup with Yellow curry buns?
how about the same setup with Sanguine Scythe instead of Apoc?

Or is it too close to tell (Don't count evasion, subtle blow or any other utility factors).

Depends on what you're fighting.

You need to know your critical hit rate to know how much of an increase in damage you gain from iga necklace.
And since we're talking inside abyssea, I suggest this:

With GN, RR and Apoc. Even without Blade: Hi.
(Augement Haidate with crit damage 4%)

I don't have augmented byakkos, so I wasn't going to bother with haidate/dusk for the 11 more DEX in abyssea, trading off the attack and acc since they are both fairly equal on both peices, and even though its a small increase the occ attack twice in off hand is > 11 DEX (inside).? I'm not saying this is correct this is just my line of thinking. With the dusk+1 price dropping I'd rather just wait till it gets lower and then shell out, unless it's a massive improvement. (outside abyssea I have other options to play typically). If someone wants to change my opinion feel free.

To be honest I just don't have access to someone with synergy leveled up and haven't looked into the easiest way to go about getting my sky augments yet.

If/when I get my kitty pants upgraded I'll think about switching.

For the original question:

I thought for argument sake inside, with GN and RR that crit rate was capped? Am I wrong?

Looking at 90 weapon mobs, zone bosses things like that I guess. Obviously in an attack capped situation agasaya's is useless.

How about if I ask it this way. 2% increase to crit damage. Lets say my crits do 250 (over estimating here I think) then that 2% amounts to about 5 more dmg per crit. How much attack is required to make 5 more dmg per crit?

Not sure if it can be worked out this way?

Thanks

Oh and also, are you implying that SS is useless other than adding some HP when comparing Apoc to SS? Cause I have been using both combos alot and I like both of them, but hey the more answers I have the better :P

The only cap there was on critical hit rate if ever was 95% so RR GH and dDEX didn't cap you although it does have diminishing returns like most stats which is why chainmail still parses higher in most cases from a purely damage standpoint. With red curry and berserk I'd think you would probably benefit more from the Iga than aga in scars and visions stuff with a few exceptions. Some of the heroes stuff has some pretty dirty defense though and ninja is a job that's often a lil short on attack and accuracy.

Iga neck in this situation, tiercel if you decide to use full empyrean (heavy stats for strong mobs).

One of the biggest misconceptions people make is how much apoc increases your overall DOT. Don't replace it with SS (as previously mentioned).