I use AMR for my gearing purposes. I pay for it so I have access to BiG feature. It's pretty amazing. It give me an entire set of gear to wear based on what's in my bags/bank instead of just looking at a singular piece and saying it has the right stats and they are better than the last item I had on, only to find out that I'm over the crit cap or something silly that invalidates and item being better.
Last night I got a couple new pieces so I did my usual thing and ran the BiG feature. Something vastly different from what I expected happened though. My gear all switched out. Well 4 pieces of it that I had pretty much abandoned. My enchants went from Vers to Mas, as did my gems. So I checked everything. My settings, my spec, I reset my cache, used another browser. Everything I could think of. I checked their forums for any bug reports. I came here to see if there had been a hotfix I wasn't aware of. Nothing pointed me to why I was getting mastery. There is a small note on Icy-veins that secondaries might change up a bit. But I paid that little mind. The note seemed so insignificant for whatever reason.
So I decided to check another means of gear check. Shadowcraft. I imported my character, and I expected to find that I was correct. That AMR was broken. That's not what I found. Shadowcraft, even before switching out my gear, had me enchant and gem Mas. I updated the gear based on the AMR recommendations, and the expected DPS on Shadowcraft shot up too.
In the end I'm down 2 lvls, but my DPS (Shadowcraft expected) went from 258819.10 - 276261.0 depending on a couple pieces, that's like a 10K DPS increase. I only attempte Ursoc after, which was my guild's first time in there, but my DPS was only down a little bit. Which I expect is more from me running around trying to avoid death after it was obvious we were going to wipe. In other words I have no real world experience with the performance of Mas yet.
So is Mas a thing? Is anyone else experiencing this?