For example, if you have 200 int, agi, or str, 1% of versatility adds 1% dmg which equals 2 of the primary stat. But at 300, 1% gives you 3. I was thinking of making a simple spreadsheet to calculate. I want to get the Nightsky Sash which is 11 int / 10 stam, but my int, haste, vers, gloves may give more damage, or the same. The same damage would be better as it mitigates damage too.
There are a bunch of stat whores, or whatever you want to call them (no offense) that max out the primary, even though it does less damage overall. It just looks MANLY! I took less int on my mage (271 now at 29), and added some versatility for more or the same damage, with some damage mitigation. Haste also becomes more potent when going glass cannon style. But that is harder to figure as it also lowers the GCD. Was thinking of trying a haste whore mage. The missiles at 35-40% haste would be hilarious!