I parse regularly using twash + Izii. Main handing Iziikoh ALWAYS pulls ahead of main handing Twash. A recent example-
I did a SKC20 on difficult with my LS. I main handed Twash and sub Izii for the fist three, then switched hands for the last three.
First three-
THF- 33%
MNK- 27%
DNC/SAM (me)- 22%
Last 3-
THF- 31%
MNK 25%
Me- 27%
(the remainder of both is the PLD soloing the RNG trying to get it to use EES)
Same buffs, same gear etc... only difference is me switching the hands i have my daggers in. I also entered each fight with close to 300% TP bc the THF was DBing a BRD so we would wait for Night/Troub to be rdy b4 entering, which should have given Twashtar a significant advantage being able to put up AM3 ASAP...
Same thing happens when i'm soloing. Main handing Iziikoh always nets me a higher exp/hr...
The ODD does not make up for Twashtar's excessively low base dmg... Its intended to be a Main hand weapon, but it cant perform as one. Which is why i've started calling it Crutch-tar. Main handing it means I need to put in the additional effort to maintain AM, but i'm not gaining anything by it.
SE should just replace the ODD on it with a costum effect- Maat. Turning me into an old man would at least be funny.