For those people who are looking for some content of the shadow priests in 7.1.5. ive made a video and you can see it below. Its not the best yet, but it is just to give you a idea.
UPDATE:
Remember my ilvl in this video is 838, now im at 843, and I can clearly notice the damage buff you get ones you reach ilvl 840. tomorrow 25-01-2016 I will be posting a new video on this chanel.