Well it's not like I have a personal bias towards PvP power or anything. I use SimCraft to determine how much DPS each of the main stats give, and then I am able to calculate exactly how much DPS 1 point of PvP power gives, and compare them from there. SimCraft is pretty damn accurate, and the math should check out.
Just plug the stats into my spreadsheet to get a rough idea. Use the values on rows 29 - 38 (left side column).
So the stats for the PvE piece would look like this: =783*B29+628*B34+412*B36+640*B34+120*B29
And the PvP piece: =1078*B29+416*B32+772*B35+462*B37+276*B34+320*B34+60*B29
Which gives the PvE piece a DPS value of 6967 and the PvP piece 7592.
Since those PvE shoulders are itemized so perfectly (and the PvP ones so terribly), it wouldn't surprise me if the 512 PvE piece ends up being better than the 522 PvP, but I'd need to know the exact stats to say for certain. Does anyone know a reliable way to determine the exact stats of scaling gear up/down? I can get a rough estimate by comparing different item levels of it, and assuming it scales linearly, but I'd like to get some exact numbers before I put any work into comparing a bunch of PvE pieces to PvP.