Basically, a reference design but with a little more length and lower quality VRM components than the ones found in AMD's reference card. I know a lot of AMD fanboys here that like to recommend the RX 480, but I would implore against recommending this particular AIB.
It looks like Power color still has a long way to go in terms of their build quality. In all likelihood, the ones sent out to reviewers are engineering samples.
Personally I would always go with Sapphire cards. Maybe I am a bit brand fanboy but I like what they are doing. The coolers are always really good, the cards are fast, well built and Sapphire doesn't focus just on looks.
However, there RX 480 Nitro isn't perfect either. Fans on them have been proven to be just us noisy as the reference card which is mind boggling in an AIB. I forgive them in this instance however, because they probably had to cut back on other aspects to facilitate their hot swappable fans in other to keep the price well below $300 to be competitive. If it was a Nitro 390x back at that time I'm sure they would've used higher quality fan motors for the hot swappable fans.
I had just come across this channel this morning, because of these PCB overviews. I love them. Some tech sites go through the trouble of listing what components make up the VRMs, but nothing quite this indepth.
I was shocked at how "poor" the Gigabyte model was, and am excited for when he does the XFX/HIS models - supposedly those are the best of the bunch.