This spell is basically replacing the 3 buffs you currently use for AC and HP.
At level 44 using Resolution/Symbol of Naltron/Armor of Faith:
+HP: 637
+AC: 11
At level 44 using Temp:
+HP: 800
+AC: 12
Other considerations:
1) Both temp and the symbol/reso/AoF combo stack with Armor of Protection (self HP/AC buff),
2) temp lasts way longer than the symbol/resolution/AoF combo,
3) fewer buffs to cast using temp
4) temp costs 510 mana and the symbol/reso/AoF combo costs 575 mana
Sooo in conclusion... Why use the other buffs at these lower levels? I'm not sure.