I am 8/10 on Body seals and will soon face the question of fulltiming the Tantra or using it as an impetus macro piece.
Tantra Cyclas +1 - 61 DEF, +12 ACC, +12 ATT, STR +8, VIT +8, Augments Impetus
Aug Kirin's Osode - 52 DEF, +7 ACC, +10 Stats, +50 Light, +2 Dual Wield
Ignoring stats that have no real meaning on MNK, we are left with:
+5 ACC, +12 ATT, Aug: Impetus Vs +2 STR, +2 VIT, +10 DEX, +10 AGI
So, essentially does +12 ATT beat out +2 STR, +10 DEX. My kneejerk reaction was Osode would still be better with Tantra as an impetus macro piece.