Important: All our testing has been performed with updated BIOS files provided by ASUS. I uploaded them here and here.

The ASUS R9 290X DirectCU II is the Radeon R9 290X done right, which sets the bar very high for upcoming R9 290X cards. In our testing, the card successfully improved on all shortcomings of AMD's latest high-end graphics card. Its overclock out of the box makes the card 3-4% faster than the stock R9 290X. ASUS has also not only overclocked the GPU frequency as even the memory received a bump in clock speed, which is rare nowadays. While AMD's reference design often throttled to prevent itself from overheating, the ASUS card doesn't have such issues. Compared to NVIDIA's GTX 780 Ti flagship, we see the card 7% slower; and 3% faster than the GTX Titan.
Power heat and noise have been the R9 290X's biggest enemies, and the ASUS R9 290X handles them very well. The ASUS DirectCU II heatsink with its two fans provides much better cooling than AMD's stock thermal solution. ASUS also decided to include two BIOSes, quiet" and "performance", with their card. Both provide the same in-game performance as there is no performance penalty when the "quiet" BIOS is active. Selecting the active BIOS allows you to pick between low temperatures with noise levels that are just somewhat improved over the AMD reference cooler or low noise levels with temperatures that match the AMD reference design. I personally find the noise levels in quiet mode better than what I expected from a custom design R9 290X, which makes the card a real option for noise-conscious gamers. The card is still not as quiet as other custom design GTX 780 Ti cards we tested recently (which are also much faster), but it shows that not everything is lost when it comes to the power/heat/noise of AMD cards. Temperatures in quiet mode reach 94°C, which seems high, but modern video cards are designed to withstand such temperatures just fine. Performance mode offers low temperatures of just 78°C during gaming, so you can opt for the performance BIOS if you feel 94°C to be too much and can live with more noise, although there is really no reason to. The "performance" BIOS should have been called the "cool" BIOS since performance is exactly the same, no matter which BIOS you use.
Overclocking of our card ended up a bit lower than on other R9 290X cards we tested before, but the differences are kind of small. My only wish would have been for ASUS to use Hynix memory instead of these Elpida chips which do not overclock nearly as well as chips from Hynix or Samsung. A welcome addition is the backplate - it helps prevent damage to the card during installation and gives the product a much nicer look and feel. You are also free to customize the color theme of the card by using the included red (ASUS ROG) or golden (ASUS motherboards) stickers. I also like the clean black theme without any stickers attached.
I've seen the ASUS R9 290X DirectCU II listed at Newegg for $699, but ASUS tells me this is a completely unrealistic price. ASUS says to expect a price of around $599, roughly 5% over reference, and pricing in Europe matches that expectation. Newegg is probably just looking to milk pre-order buyers hoping to finally get a custom design R9 290X card. If the card really ends up with a $699 price, it'll be a complete waste of money. You'd be much better off getting a custom design GeForce GTX 780 Ti, which would be significantly faster and quieter. However, the card is an interesting option at ASUS's projected price of $599. It clearly beats the reference design cards in all metrics you could think of, and the $100 price difference to a GTX 780 Ti could go into upgrading a different piece of hardware, although spending an additional $100 probably wouldn't make much of a difference if you are in the market for a $600 graphics card.