Someone Somewhere :
Bigger companies will have more top engineers though.
TBH, I wouldn't really buy a card from the last three on your list. Supposedly XFX's coolers are pretty useless, and the Powercolor and HIS are nothing much to write home about.
I'd go for another 7970. Generally the best coolers seem to be Saphire, Gigabyte, or MSI (and Asus too, but they're out).
Well let's see, I've had 2 XFX Radeon HD 4870s in Crossfire for oh, four years now with no problems whatsoever. That's after having run one XFX HD 4870 for almost two years before I got the second one for Crossfire. XFX also has that crazy "double lifetime warranty". Powercolor makes THE fastest Radeon HD 7870 (PCS+) and HIS makes the coolest-runnig HD 7870 (IceQ). I've been building computers for 25 years now (jeez how old am I? LOL) and I've used cards by Palit, XFX, ATi, nVidia, EVGA, BFG, Sapphire, PNY, Powercolor and ASUS. The only time I ever used an ASUS card was the ASUS Radeon HD 3450 AGP card (AH3450/DI/512MD2) which I got as a gift for my mother so that she could use her old AMD Athlon 3800+ computer to watch HD video on her 52" Sony Bravia. The first card lasted about oh, 10 months and it failed. I sent it in to ASUS, and they supplied me with a replacement. The second card died about a year and a half later, now out of warranty. I have never seen 2 cards die in under 3 years, especially low-end ones that are active-cooled. If you look around on google, you'll see that ASUS branded video cards have all kinds of problems. I've seen one XFX card die and it was a GeForce 6200 256MB AGP card that was about nine years old. Out of principle, I didn't claim warranty on it. If a card lasts 9 years and dies, I have no complaints. Most video card manufacturers are very good at what they do. My judgement of ASUS is only on their cards because their motherboards are fantastic. ASUS goes in the category of brands I won't touch like Diamond and VisionTek when it comes to video cards though. To prove the point even more, Sapphire is known to be a top manufacturer of Radeon cards and one of the original three ATi add-in partners along with HIS and Powercolor. However, their motherboards are an absolute disaster. Sapphire is a brand name owned by PC Partner who also makes motherboards under their own name. Because their main focus is video cards, their motherboards are absolute crap. Just because a company makes a great product in one market doesn't mean they'll make a great product in all markets. AMD themselves are a perfect example of this. AMD is pretty much dead-even with nVidia and leave Intel in the dust as far as graphics are concerned but fall flat against Intel for CPUs. As much as I hate Intel, there can be no denying that their CPU technology is superior to AMD. Again though, Intel's graphics processors are complete garbage so draw your own conclusions about that. I use AMD only for two reasons, I hate Intel and AMD generally offers better value in my price range. Always remember, Google is your friend. Google things like "<name> Radeon problems" and you'll be much better informed as to what is good and what is questionable. Cheers!