Is this a decent card for the price?
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161315
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161315
Sure. I mean it's okay. I used to have pretty much the same thing.
What's your whole system's specs?
And what resolution do you play at?
Athlon 64 X2 2.70 GHz
3GB of RAM
playing at 1920x1080
Ouch. Mine could barely handle 1280x720, and I overclocked my processor quite high.

CSS isn't much of a graphics hog it wouldn't stress a card like that. I played CS on high settings on a HD4350 that came stock in my computer and had no issues. It runs a quite a bit more smoothly on my 5850 though.
The 4670 isn't a bad card if your playing source games. If you want to play games like Bad Company 2 or STALKER for example though you would need something with a bit more oomph then the 4670. I can guarantee you that the 4670 isn't going to handle 1920x1080 Resolution in higher end games unless you have the settings all cranked down and you run the games in DX9.
Spend another $100 and get this
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150447&cm_re=5770-_-14-150-447-_-Product