I decided to purchase an R9 290x once I found that the 300 series was just a slightly better remake of the 200 series, and when looking at cards, I found that Sapphire was the only one who had a custom pcb version come out recently. Knowing that Sapphire tends to be AMD's go to for testing hardware, I decided to jump on it, and it seems that besides the vram, this newer Sapphire model really matches up to the new 390x design changes.
It's been a world of difference coming from my 6870 to this as well. Posting a photo of the card in my case as well as the comparison in 3dmark of old card and new card. If you want to see more photos of my build, check out my prior build posts.