|Brendan Green Venture-Captain, Alaska—Fairbanks aka Relmer|
The "super high AC" train does seem to be more prevalent today than it was even a year ago, although it has always had some presence.
I am currently playing through Eyes of the Ten with a ranged Paladin that has a 21 AC (+1 Mithral Shirt only). Her defense is not deflecting attacks but having insane Saves and being able to heal 400 HP on average every day (4x her total HP) as a swift action, with another 280 HP outside of combat. All I had to do to get that was to pick an Archetype and invest in 1 feat.
To be honest I am glad I did not invest in AC when, during the last session, one of the "Super AC Tanks" in my party (which is basically everyone but my character) nearly died after missing a save on a spell that would have required him to pay for a True Res or a Wish to get his character back (a 1/session re-roll saved him).
High AC is great, except when you have a less than a 50% chance of making saves against save-or-retire spells that a slotted Clear Spindle Ioun Stone does not defend against. Even at level 8, per the OP, I question the value of sinking so many resources into not getting hit.