I just think they are kind of frowned upon nowadays. It's generally considered best to have the fewest number of components from source to speakers - less stuff to potentially "mess up" the signal.
Having said that, if you are running straight stereo, and want to EQ for your room - it's not a bad idea at all (in my opinion). I use one that I got off ebay cheap, and works fine. There one there now:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3086270079&category=3271
if you don't mind the 80's looks, it specs out good on paper, and mine at least doesn't have any scratchiness in the sliders at all. I mainly bought mine for the variable rumble filter, which is nice if you listen to vinyl.
Just remember if you are using an EQ - don't move the slider up - just down. That way you are only applying resistance, not trying to boost the signal. If the signal needs boosting, that's what your volume control is for