If you are using Cadd, I wouldnt deff recommend getting the 6 core like tertal said, you will end up saving alot if you ever decide to upgrade again...just sayin.
the cad work i do isnt very serious, also not in 3-d, the single core POS's at the school manage almost lol
i am not trying to negate your points, just proving that i have put thought into it
fyi, my parts have been ordered and are in the mail, no changin now, for a while anyways