Dummy testing is really not sufficient for what you're trying to test.
Originally Posted by Kaejin
I don't know how much haste you had before you reforged, but with 2p t13 the amount of haste you need before hitting the GCD cap is drastically lowered even for Oblit heavy priorities. You should be adjusting your haste levels until you find a spot where you're not wasting resources. Around 1800 to 1900 haste rating is a good place to start exploring.
When I reforged to a mastery-heavy build, I'm sitting at 1739 Haste and 1758 Mastery. On the tests I've ran on dummies today, I did not have one Moment in my rotation where I was starved for Runic Power OR Runes.
I changed my Spec to incorporate IBT versus my prior 2/3 Epidemic build.