They have said that your pc "should" run civ v better than it ran civ iv. I have an i7 860 and a gtx 275 and even civ iv isn't smooth as butter(the graphics Is las gen but still) at certain points of the game. However from what they say I suspect V will run much better. If your pc just barely scraped by with civ iv, I don't think they can do anything to male V run that much better, atleast enough for you to notice. If you are planning on keeping your old pc, think if you want another 5 plus years of that experiance

with V that you've been having with iv.
A good gaming pc can always be used for surfing the web, and typing reports and sending emails. A home office pc can always be used for surfing the web, and typing reports and sending emails, but will never be a good gaming pc!'
Just don't go and buy a pc if it sounds good, ie quad core with 8gigs ram and a 1gb graphics card!! Sweet!! Chances are the processor is too slow, the rams crap, and the graphics are a 6 year old rebranded model!! Cough nvidia cough! Reaserched each part yourself, don't ask people here, because half the time they might be wrong or might not know and guess. Read legit reviews, not user reviews, people are idiots, and may love something that's crap, just because they don't know better. Also never listen to sales people!!! They are mostly liars who will sell you sh@t for a commision!! This is all from personal experiance!! Your best bet is to build your own from the ground up, you'll get what You want and not what a company wants you to want! It's cheaper(most of the time, unless you have expensive tastes

) and you'll have a better understanding of what you own!!
This is all my opinion, and is just a general statement!