I've got one ring inside a clan chest reward so i decided to make this excel sheet to compare my DPS with a tauti ring.
I only did it on a NPC, and i didn't measure its PVP bonus.
Here is my excel sheet : https://docs.google.com/spreadsheets/d/1CyP9xmkZA8E3A1AVGsZAzDJ3fk2hBzL0wF6ApMrtrMQ/edit?pref=2&pli=1#gid=1440720349
Here are screenshots :
* AQ + Istina
https://www.ezaya.fr/AQ%20Istina.jpg
https://www.ezaya.fr/AQ%20Istina%20Brooch.jpg
* AQ + Tauti
https://www.ezaya.fr/AQ%20Tauti.jpg
https://www.ezaya.fr/AQ%20Tauti%20Brooch.jpg
* Tauti + Istina
https://www.ezaya.fr/Tauti%20Istina.jpg
https://www.ezaya.fr/Tauti%20Istina%20Brooch.jpg
To conlude, at least for PVE because i didn't measure its passive for PVP, i'll keep AQ + Istina.
Maybe AQ + Baium is better but i don't have it ! So... maybe later :D
Even with 169-179 M. Critical, i was able to do around 34-35% critical hit with AQ+Istina & AQ+Tauti, while i did only 28% critical hit with Tauti+Istina (159 M. Critical).
But those critical stats are kinda fake because the NPC should be Dark BLUE for me.