ok lets do this:
Augmented Shire Astrometer
Class: AST
Item Level: 270 Req. Level: 60
Damage: 114 (Magical)
Delay: 3.20 Auto-Attack: 89.60
Sells For: Unsellable Materia Slots: 2
Bonuses
Vitality +184
Mind +182
Piety +138
Critical Hit Rate +97
Augmented Shire Preceptor's Belt
Class: CNJ, WHM, SCH, AST
Item Level: 270 Req. Level: 60
Defence: 119 Magic Defence: 208
Sells For: Unsellable Materia Slots: 1
Bonuses
Vitality +79
Mind +78
Critical Hit Rate +59
Spell Speed +42
Augmented Shire Preceptor's Coat
Class: CNJ, WHM, SCH, AST
Item Level: 270 Req. Level: 60
Defence: 192 Magic Defence: 336
Sells For: Unsellable Materia Slots: 2
Bonuses
Vitality +171
Mind +169
Piety +128
Spell Speed +90
Augmented Shire Preceptor's Gloves
Class: CNJ, WHM, SCH, AST
Item Level: 270 Req. Level: 60
Defence: 137 Magic Defence: 240
Sells For: Unsellable Materia Slots: 2
Bonuses
Vitality +105
Mind +104
Piety +55
Spell Speed +79
Augmented Shire Preceptor's Hat
Class: CNJ, WHM, SCH, AST
Item Level: 270 Req. Level: 60
Defence: 137 Magic Defence: 240
Sells For: Unsellable Materia Slots: 2
Bonuses
Vitality +105
Mind +104
Piety +55
Determination +76
Augmented Shire Preceptor's Hose
Class: CNJ, WHM, SCH, AST
Item Level: 270 Req. Level: 60
Defence: 192 Magic Defence: 336
Sells For: Unsellable Materia Slots: 2
Bonuses
Vitality +171
Mind +169
Critical Hit Rate +129
Determination +86
Augmented Shire Preceptor's Thighboots
Class: CNJ, WHM, SCH, AST
Item Level: 270 Req. Level: 60
Defence: 137 Magic Defence: 240
Sells For: Unsellable Materia Slots: 2
Bonuses
Vitality +105
Mind +104
Piety +79
Determination +53
Augmented Shire Preceptor's Bracelets
Class: All Classes
Item Level: 270 Req. Level: 60
Defence: 1 Magic Defence: 1
Sells For: Unsellable Materia Slots: 1
Bonuses
Mind +78
Piety +59
Critical Hit Rate +42
Augmented Shire Preceptor's Choker
Class: All Classes
Item Level: 270 Req. Level: 60
Defence: 1 Magic Defence: 1
Sells For: Unsellable Materia Slots: 1
Bonuses
Mind +78
Piety +59
Determination +40
Augmented Shire Preceptor's Earrings
Class: All Classes
Item Level: 270 Req. Level: 60
Defence: 1 Magic Defence: 1
Sells For: Unsellable Materia Slots: 1
Bonuses
Mind +78
Critical Hit Rate +42
Spell Speed +59
Augmented Shire Preceptor's Ring
Class: All Classes
Item Level: 270 Req. Level: 60
Defence: 1 Magic Defence: 1
Sells For: Unsellable Materia Slots: 1
Bonuses
Mind +78
Determination +57
Spell Speed +42
Proto Ultima Ring of Healing
Class: All Classes
Item Level: 270 Req. Level: 60
Defence: 1 Magic Defence: 1
Sells For: Unsellable Materia Slots: 1
Bonuses
Mind +78
Critical Hit Rate +59
Determination +40
so overall you would have for ilv 270
-114 weapon damage
-919 defense
-1605 magic defense
-920 vit
-1300 main stat(casters share stat weights with healers so we can measure dps too)
-1665 secondary stats
Now lets check lv 68 gear since you said were running that gear in Castrum Abania
Palladium Planisphere
Astrologian's Arm
Item Level 285
Magic Damage
122
AST
Lv. 68
Bonuses
Vitality +196 Mind +211 Critical Hit +142 Spell Speed +203
Twinsilk Hood of Healing
Head
Item Level 285
Defense
230
Magic Defense
402
CNJ WHM SCH AST
Lv. 68
Bonuses
Vitality +112 Mind +121 Spell Speed +81 Piety +116
Gazelleskin Coat of Healing
Body
Item Level 285
Defense
322
Magic Defense
563
CNJ WHM SCH AST
Lv. 68
Bonuses
Vitality +182 Mind +196 Critical Hit +188 Spell Speed +132
Gazelleskin Bracers of Healing
Hands
Item Level 285
Defense
230
Magic Defense
402
CNJ WHM SCH AST
Lv. 68
Bonuses
Vitality +112 Mind +121 Spell Speed +81 Piety +116
Twinsilk Sash of Healing
Waist
Item Level 285
Defense
199
Magic Defense
348
CNJ WHM SCH AST
Lv. 68
Bonuses
Vitality +84 Mind +90 Critical Hit +61 Piety +87
Twinsilk Slops of Healing
Legs
Item Level 285
Defense
322
Magic Defense
563
CNJ WHM SCH AST
Lv. 68
Bonuses
Vitality +182 Mind +196 Determination +188 Piety +132
Gazelleskin Boots of Healing
Feet
Item Level 285
Defense
230
Magic Defense
402
CNJ WHM SCH AST
Lv. 68
Bonuses
Vitality +112 Mind +121 Critical Hit +116 Piety +81
Molybdenum Earring of Healing
Earrings
Item Level 285
Defense
Magic Defense
1
CNJ WHM SCH AST
Lv. 68
Bonuses
Mind +90 Determination +61 Spell Speed +87
Palladium Choker of Healing
Necklace
Item Level 285
Defense
1
Magic Defense
1
CNJ WHM SCH AST
Lv. 68
Bonuses
Mind +90 Spell Speed +87 Piety +61
Palladium Bracelet of Healing
Bracelets
Item Level 285
Defense
1
Magic Defense
1
CNJ WHM SCH AST
Lv. 68
Bonuses
Mind +90 Critical Hit +61 Piety +87
Palladium Ring of Healing
Ring
Item Level 285
Defense
1
Magic Defense
1
CNJ WHM SCH AST
Lv. 68
Bonuses
Mind +90 Critical Hit +61 Piety +87
Palladium Ring of Healing
Ring
Item Level 285
Defense
1
Magic Defense
1
CNJ WHM SCH AST
Lv. 68
Bonuses
Mind +90 Critical Hit +61 Piety +87
So overall for ilv285 you have
-122 weapon damage
-1538 defense
-2685 magic defense
-980 vit
-1506 main stat
-2464 secondary stats
Now lets compare shall we overall by remaining in ilv270 gear you lose
-8 weapon damage
-619 defense
-1080 magic defense
-60 vit
-206 main stat
-799 secondary stats
All this can be carried over to caster dps as well
You were a hindrance to any party you were in with that gear in Abania and i feel sorry for anybody you were grouped with when you did it you caused unnecessary stress on your healer(when you weren't healing) and doing far weaker damage than you should have been by a significant amount 8 Weapon damage is huge, 206 main stat is huge, 799 secondary stats is huge.