Never had any problem with my AMD on AH or any other game. Most people here do prefer Intel. In my not so humble opinion the performance difference between AMD and Intel dual cores does not justify the higher cost of a Intel chip. AMD 3.0-3.2 Mhz dual cores run about $110-125. Intel 175-275?
AMD only produces mid range quad cores. Intel has mid range to the top dogs. However, head to head at comparable speeds Intel quad's outperform the AMD and at a comparable price. A Intel 2.4 quad is about 190$ while the AMD 2.5 is about $175.
Currently a quad core is over kill for AH. But multi-core's are the future. So it depends on your other uses for it.
My AH system; 3.2 GHz AMD x2, Asus M2N SLI MB, 8800GTS VC, 2 GB Ram, 150 Raptor, 600 Watt PSU, Antec 900.