As I said, I dislike.
PfA is an accessible spell that protect from some devastating spell effects, given the right circumstances are reached.
Its because Pf Aligment is a level 1 spell and nearly universal amongst class that all subsequent Mind Affecting spells are balanced. When implementing "win" spells you can do so and still maintain balance by providing a readily available deterrent. This 3.x philosophy was even extended to the herbalism craft on PotM in cases like See Invisibility being a lower DC than Invisibility.
All those spells that PfE protects against are absolutely devastatingly effective if not countered. And because PfE is easily acquired and utilized, a person caught without it is without excuse.
Balanced.
Okay Anarco. If you are on the "no thanks" side of this all, a discussion for any compromise will be impossible.
You and Emomina see a purpose in the PfA spell in that it "protects from some devastating spell effects." What spell effects are that? More importantly, how could PfA be changed so that those spell effects you talk about can be warded against and in the way make the mind blank spells more usable?
Should the PfA protect from Weird for example? Fear auras? Something like fear auras could well be protected from with +10 will as they're usually not that high a DC. The PfA could have +12 will, +15 or +20 will...it's all about the scope of those "devastating spell effects" what the + would be.
For now, I just need "devastating spell effects" to be defined.
To me, devastating spell effects are those ones who allow a one hit win. Of course we have one hit wins, many, to be honest: Veil of the Banshee, power word, finger of death, implosion, etc, etc, etc.
Weird is a strong spell? Yes, it is: it is area of effect and affects everyone there. PfE makes it useless? I doubt that: 1) you have to pay attention to the alignment. 2) In a party, will everyone be protected?
But the main question is you have alternatives and only have to plan what to to. Weird is one of the worst good spells: you need a Will AND Fortitude saves, making it almost useless against casters (will) and melee (fortitude).
So, PfA doesn't makes casters useless as some people seem to claim. Besides, all you need is a well placed dispell (or greater dispelling, or mordenkaninens disjunction) to clean the target.
On the other hand: Is it corret to make a level 1 spell (scare) be enough to kill one fighter? All you have to do is cast, attack, rinse and repeat.
The fact is that PfA is REALLY nice in the begining of the game, but helps, in the later stages, to avoid some effects, what is total and completely counter-measured, just like the thread regarding hamatullas spaming dispel showed us.