Rindomaru with Store TP +15, Accuracy +5 and Weaponskill Damage +4% vs. Hagun.
Here is a gear comparison. I did this with basically my gear set up, but the only slots that are really going to matter are those that change trying to get to the 5-hit build. I also tried to maintain full Usukane for these sets. Mix and match may results in different results.
Hagun gear for TP:
FFXIGEAR.com
Hagun gear for WS:
FFXIGEAR.com
Total delay from zero = 2619
Total delay after WS = 2183
Rindomaru gear for TP:
FFXIGEAR.com
Rindomaru gear for WS:
FFXIGEAR.com
Total delay from zero = 2250
Total delay from WS = 1800
From zero TP to ten WS it should take Hagun 22266 delay and Rindomaru 18450. So, assume no interruptions, no meditate, and a perfect world in the time it takes Hagun to get 10 WS, Rindomaru would get 12 WS. This is just an observation, for the following calculations I am just assuming you start with a WS because almost all SAM's are going to meditate before they start anything. All WS are assumed to be Tachi: Gekko also.
A few observations about delay here. First, without the sword strap there is a 20% increase in speed to the next WS going from a 6-hit build to a 5-hit build, and this is assuming you are starting after a WS (the difference is 16.7% when not starting from a WS). Second, with a sword strap on Hagun there is a 17.5% increase in speed to the next WS going from a 6-hit build to a 5-hit build, again assuming you are starting after a WS.
I am not going to get into the pDIF details because they are too complicated and too much for me right now. If someone else wanted to take this info and add the pDIF calculations I would really appreciate it.
In this scenario there is not much different in TP stats:
Rindomaru has 2 more base damage, 1 less DEX and 4 less Attack (it also has 3% more delay but I handled that above) compared to Hagun.
For WS the difference is larger:
Rindomaru has 2 more base damage, 6 less STR, 9 less Attack, and ~3.5 DEX related Accuracy but it does have 4% WS damage (depending on when this procs can make a big difference).
Here is the difference in WS calculations:
For Hagun, D = 75, fSTR2 = 37, WSC = 79 and fTP = 1.825. This gives a damage value of 358 * pDIF.
For Rindomaru, D = 77, fSTR2 = 34, WSC = 76 and fTP = 1.5625. This gives a damage value of 292 * pDIF. But also remember that Rindomaru is going to have a 4% increase in (assumed) total WS damage.
Also, we need to consider the 19% damage increase from Overwhelm. In this perfect example we will consider all WS to benefit from Overwhelm.
I absolutely HATE doing this but I am going to use Greater Colibri because of their known values for the next set of assumptions. If you have the value of better mobs to check this on then please feel free to add them. Greater Colibri are especially bad because both weapons are going to have their max pDIF capped, which will not happen on just about any mob that is more difficult. Also, all of this is completely wrong anyway because the old formulas have been proven to be inaccurate and I don't think we have definitive new calculations.
So for Hagun we have Damage = (358 * 2) * 1.19 = 852
And for Rindomaru we have Damage = ((292 * 2) * 1.19) * 1.04) = 722
Moving on, to get an exact equal amount of WS in the same amount of time, you have to go out to 2183 WS for Rindomaru and 1800 WS for Hagun.
So for Hagun you get 852 * 1800 = 1533600
And for Rindomaru you get 722 * 2183 = 1576126
In the end, in this perfect situation you should see a 2.77% increase in damage over that time. Haste should not make a difference in this calculation.
So that means you should run out and get a Store TP +15, Accuracy +5 and WS Dmg +4% Rindomaru, right? RIGHT?
Not so fast. This is the perfect scenario for Rindomaru with a perfect Rindomaru. As accuracy falls (this scenario assumed perfect accuracy) and especially as mob strength increases (this is especially important because Greater Colibri are one of the weakest common opponents in the game and Rindomaru was just barely capped with Tachi: Gekko) this will very quickly revert to Hagun being the dominant GKT again.
In full disclosure, I will be keeping my Hagun, and I might try to pick up a Rindomaru, but I don't think I will use it for much of anything. As I have said before, I do not gear myself for XP parties, I gear myself for important mobs. If you are the kind of person that has a polearm build for your SAM then a Rindomaru might be right for you. But then again, a Rindomaru isn't going to beat a polearm build on Greater Colibri, so that is kind of self-defeating. On anything of more difficulty than a Greater Colibri though, the Hagun is still the right choice.
If anyone has a problem with the builds I used, my calculations, or any of my assumptions just let me know and I will try to fix them.