As far as I remember, MDMG+ added some straight damage to post-fTP, but before MAB.
Speaking for myself (probably not optimal):
242 DEX
195 INT
MAB+138
2.9375 fTP (1000 TP + Moonshade Earring)
i119 dagger
32 fINT (capped, probably unrealistic assumption with just 195 INT)
Base damage: 119 + 2 + 0.4 * 242 + 0.4 * 195 = 295.8
Multiply with fTP: 295 * 2.9375 = 866.5625
Add fINT: 866 + 32 = 898
Theoretical damage on neutral stuff at 1000 TP: 898 * 2.38 = 2137.24
Assuming those numbers above, we can conclude a few things:
* MAB+1 is worth somewhere between MDMG+8 and MDMG+11.
* MAB+1 is worth somewhere between INT+8~9 and INT+20.
* INT+1 is worth somewhere between MDMG+1 and MDMG+3.
The upper and lower limits of the ranges are not exact, but rather guesstimated. They however should be useful for you to get an idea on how useful adding to a certain stat actually is.
Keep in mind that MAB+1 adds more damage with larger base damage, while MDMG+1 is a constant
1 * MAB/MDB * other multipliers, damage-wise. And INT+1 adds
(0.4 * fTP + 0.5) * MAB/MDB * other multipliers at best.
Edit: For lulz, my Aeolian Edge set.
ItemSet 336185
I can't be bothered with argochampsa mantle or acumen ring, because my bags are way too full already... also, *** augmenting even more Taeon gear!