If you have really good deal for 7970 there is no argument that could blow you away from it.
Don't take prejudices in computer world. Every manufacturer will have bad days but that does not mean that they are bad
12 years is a long time, and that is when Ati was pretty dominant over Nvidia series with their 9000 series cards.
There is no modern video card that has not had some issues.. google and you'll find a ton of posts for every model.
I'm mercedes type of guy. If someone gives me brand new BMW 730i with 30% disccount i would not think a second to take it over mercedes.
If you need it, buy it. I would go for that