Alright, so, I'm goofing off with the optimal gear mechanic. I picked up a pair of Canvas Slops which are optimal at rank 26, Suits all classes so I'm not fighting with that component atm.
Now, Stats on this: Def 41 MgDef 20 Eva 32
Alright, easy enough.
Start out simple, nice Level 1 Thaumaturge.
Stats with Slops: Def 88 MgDef 84 Eva 94
Stats w/o Slops: Def 72 MgDef 76 Eva 73
Stat Difference : Def 16 MgDef 8 Eva 21
Wait. Wut? It's worth 16 of the 41 of Defense at suboptimal (39%), 8 of the 20 Mg Def (40%, still good), and 65% of the eva. Ummmm, alright...
Alright, swap to level 12 Lancer:
Stats with Slops: Def 91 MgDef 82 Eva 88
Stats w/o Slops: Def 70 MgDef 71 Eva 64
Stat Difference : Def 21 MgDef 11 Eva 22
So, 21 of 41 (~50%) Def, 11 of 20 MgDef (55%), and 22 of 32(68%)
So the Eva value really didn't change in 12 levels, but I got better defense out of it. Well, at half of optimal I'd expect to see about half of the gear's effectiveness, so this makes some sense, I guess.
Let's take an optimal piece of the same base type (cloth) for my Lancer at 12 (forget the starter equipment, these slops even at 40% destroy those starter tights...)
Hempen Tights: Optimal Rank: 6 Def 18 MgDef 14 Eva 20
So, I'd have defense -3, mgdef +3 and Eva -2. Why the heck am I carting around these tights? There appears that over time you won't be mucking about with the 15 million gear sets for level-locks and the like.
Anyone else done more experiments that would prove this statement wrong?