So I do not have the 7970 but got the HD7950-DC2T.
I kind of believe my Matrix 580 was defective from day one so hard to say it that is the reason the HD7950-DC2T is so much faster on most things.
Tested in so far:
Battlefeild 3 - It black screens if I set everything to ultra but runs fine at High settings and really low temps - even when at 1040 Core Clock it maxes at 56' temps
However the Matrix would run ultra in BF3 fine.
Battlefeild 2 - Sometimes in heavy smoke it starts to crawl but I believe that is the crap code in BF2
]Shogun 3 - Maxed everything runs smooth
FSX - this is where it blows the Matrix 580 away. I run tons of addons - Ultimate Traffic 2 max traffic, Orbx, Shade, enb, Open Clouds, REX, Accu Feel, TrackIR w/ EZDok, and even more but it runs like butter. The Matrix stuttered.
I did build a small rod to hold up the HD7950-DC2T in the case. Unlike the 7970 the HD7950-DC2T does not have that good metal support across the top of the card so it sagged down a good bit.
So I am happier with HD7950-DC2T plus i hear that Asus had a manufacture problem with overheating 7970 cards but this one runs super cool even under heavy strain and OC.
i7 4930k - Rampage IV Black Edition, CORSAIR Vengeance 32GB, EVGA GTX 780 Classified Three 27" Screens, Obsidian 800D, COOLER MASTER 1000w Gold Series, Samsung 840 Pro SSD, 2x -WD 750GB 7200 RPM SATA 6.0Gb 64mb cache 2x - VelociRaptor 10000 rpm, ASUS Xonar Essence STX / Windows 7 Ultimate 64