Your sources are most likely what the community has dubbed, "Fan boys" or, "People who hold the naive belief that one company is complete trash with no evidence to back it up, and only because they currently own an item from another company."
Let me assure you that AMD Graphics do not run like crap. I am extremely satisfied by my R9 290, with only one complaint - AMD cards run hot. Compared to a 970 at full load, my card on average runs about 15c hotter, and with a lower clock. However, this won't be the case for every single AMD card, and I certainly wouldn't shy away from buying one, should a better deal arise.
This video does a good job of explaining this battle...
[video="https://www.youtube.com/watch?v=N5fi3ARXWKc"][/video]