Here is my current gear layout.

Head: L. boundless/mythic +1
Armor: +12 con/insightful radiance 70/+30 spellcasting implement
Neck: Resonation
Trinket: planar trinket (e. litany and litany swaps for clickies)
Cloak: LGS material/opposition
Belt: LGS material/opposition
Boots: 20 spellsight/+33 sheltering
Gloves: X/Potency 91/insightful impulse 66
Bracers: LGS material/opposition
Goggles: LGS material/opposition
Ring1: lantern ring
Ring2: 23% impulse lore/151 impulse

Mainhand: <various greensteel>
Offhand: golden orb/mythic +4 (Meridian fragment and +114 resonance)

Equipment augment slots:
+40 false life
+20 vitality
+2 insightful constitution
+8 intelligence
+250 topaz of power
Globe of true imperial

The idea here is that I've loaded spellpower from weapon slots as much as possible so I can freely equip any greensteel without losing spellpower.  As for defense, I'm sitting at around 1700 HP and 150 PRR.  I can probably hit close to 2K HP with a triple earth GS.  But this is enough that I can take a hit or two in LE raids.  I've completely dumped saves, as they don't seem very important in current end game. 

Criticism welcome. 

Good stuff, I haven't really thought hard about any changes you could make but one of my guildies built for DPS uses skull duggery kit for the +6 excep int skills/50 HP. Other than that, only thing off the top of my head is higher int/insightful force item.

Nice setup, I might have some ideas later.

You aren't in unyielding sent by any chance? Your HP look really high for a shiradi without maxed con gear