I don't think it's that big of a difference between the two. It has some new features, but in my opinion I wouldn't spend my money for it. I haven't even upgraded to CS2 yet (though I've used it, I just don't own it), I'm still using 7.0 and am very happy with it...it gets the job done.
If you're low on cash (like me
) I wouldn't invest in it just yet. But that's just my opinion.