AMD was really good in the athlon days, the 950 Ghz was really amazing !!!! beating up Intel in price and performance. Sadly Intel now destroys AMD in performance.
I bought a A8-5600K APU, Black Edition 3.6GHz w/ 4MB Cache no so long ago just to try it out, the thing just performs worse than a Core 2 Quad of 2.1 Ghz !!!!!! (I used to have one) like really that bad , and forget about the overclock feature uselesssssssssss.
I have a i7 4770k and a i5 2500k and a laptop with i5-3317u and I use to be a fanboy of AMD
On video cards I own two Ati 7870's, the drivers sucks, there's a issue with the mouse disappearing using crossfire, they don't know or they don't care to solve the issue. On the other hand Nvidea drivers are way better at least no issues at all and I have a GTX 560 ti and a GTX 770. On video cards there's much more than raw power to be considered.
It's just my opinion