With everyone requesting "BiS" lists to get a base knowledge of how to gear for this tier and with many of us really saying the same thing over and over again in regards to there not really being a "BiS" list per say I present you with an alternative method of gearing for T15 (Affliction for sure, haven't delved too deep into the other specs yet).
These profiles are in no way perfect and absolutely pristine but can be used to show the overall weakness of our Tier set bonuses/itemization. I did all of the profiling/reforging/gem setups by hand math and there is probably a better setup that could squeeze out more DPS potentially, but at that point it's really going to be nitpicking.
Here you can see the results:
The "BiS" profile that Simcraft shows us reflects a DPS of 203735, comparatively you can go with 0 tier gear and simulate with 203655 DPS - a difference of 80 DPS.
Keep in mind that the reforging/gemming isn't going to be perfect since I just did it all by hand so it's as close as I could figure out. But still goes to show the power of Thunderforged gear. It's also worth noting that this isn't including any upgrades, which in all honesty could put you ahead of using Tier pieces based solely on the raw stat gain advantage that you'd get.