Choosing between Two Processors

I got my computer upgraded today, and I told the vendor that I wanted a dual core processor, and it was silly of me not to mention Core 2 Duo because that's the newest one at the moment...

He got me a Pentium D 3.0 GhZ, it is dual core though. :P

What I'm thinking is, is the Pentium D 3.0 good enough? Or should I go in for a Core 2 Duo 1.8GhZ or a 2.0GhZ Core 2 Duo? I doubt I'll be able to afford the 3.0GhZ Core 2 Duo..

But still, is the D good enough or should I get it changed?

Core 2 Duo is better than Pentium D. but depends at what you need Pentium D could be "good enough".

[b]I'm a Graphic Designer mainly. But I also do some programming every now and then when required.

I run AIM, YIM, MSN all the time, and I of course have 2-3 Security Software running.

Plus I open up Adobe Photoshop, Firefox, Cinema 4D, Dreamweaver, Adobe Reader. Not always all together, but yes 3-4 apps together is no big deal.

The current CPU that you have will be enough to run those applications. With having so many open, I would maybe upgrade the RAM though dependent on how much you have installed at the moment.