your assumption the atom and the amd`s are equal is only partly true , ok the middle amd is just a notch better , but the top model is quiet a step upwards and comes with ati graphics
and not the nvidia ion onboard ,but then the price is nearly equal to the mac mini (basic model full upgrade that is ) ,
and for people who want blue ray and windows 7 there is no choice as the top zino offers this as standard,
but for people like me who see windows only sometimes unavoidable the mini is the better choice
(still have my old windows 2000 which does what i may need windows for, have it installed under Q as a guest pc on my iMac g3 600 which works fine for me 🙄 )