Well, I just realised that when using Flattering Robe, you'll lose the +10% Crimson Rock bonus damage from Hero Magic Coat (even though you can add a +5% to +20 bonus MATK with enchants), even though you'll gain +50 to +150 MATK (150 on the level range able to use HMC). In a few days we'll see how both items compare, but now I wonder what Should I do with my Hero Magic Coats. XD
I'll try simulating both scenarios in my calc later. Still, an unenchanted Flatty Robe may not be the best armor for all situations. That +10% Crimson Rock is stronger than it looks like.