Do Ion Stones protect from critical hits. Ive read a number ofthreads that say they do but have no real proof! So i ask you lot?

loun stones do indeed protect against critical hits. I assure you.

Ioun stones protect from critical hits.I have seen it happen with Aerie a surprising amount

There not supposed to, but all head-wearable items in early Infiity games were supposed to protect from criticals, so the game checks for an occupied head-slot rather than a helmet. Youd have to change a fair amount of data and re-write a non-trivial chunk of code to fix it, so id guess that its going to stay broken.