IF you oclock. Cause then the lower mhz of dc at = cost wont matter. IF you ever do multi task. IF you plan on a os like vista that really uses both cores fully. Vista is supposed to shower stronger gains from DC but its still just hearsay.
IF you use your pc for mroe then just games.
There are games out that use both cores but the numbers are against it. very limited number. But if you can afford a x2 at 2.4ghz per core or better its all good IMO. Game will move more towards DC but Id predict only once DC is mroe mainstream. With Intel bringing DC to the table as well its gonna get the ball moving even faster (top 2 are running it now).
ME I went for bang per buck. Which at time was $109 for a 3800+ single core. I couldnt justify the nearly x2 cost for the few fps gained in the handfull of games it used both cores in. Second once DC gaming is everywhere DC cpu's much faster and a better mhz per $ ratio will be around making buying one now a moot point.
Those are of course just my opinions. DC isnt a cut and dry answer kinda subject really.
How is it working? It needs a good bit of mem. Id say for a responsivbe system MINIMAL is 1gig ddr400 (yes speed matters). 2gig will be the new optimal amount. Vista is mem hungry even inits newly trimmed version. They have been trying to tweak the mem handling and its gotten alot better already.
DX10, requires Vista. So thats is when youll have to get vista. When there is a dx10 only game (you got a while) then youll need vista and a dx10 card.