This is FL Studio's default EQ, and the only one I've used (though I do hope to expand to Fabfilter Pro Q 2). It's very good, and the spectrograph is very help for finding this undesirable frequencies. Also, automating a bandpass filter in this can make some pretty good wobble sounds (I learned that trick SeamlessR ;) )
I can't produce without it. It's beautifully designed interface, along with the very pretty spectrum makes it a must-have. The automation capabilities can make this effect a very powerful weapon for super deep wubs and growls. I don't think it's quite as feature-packed as FabFilter's Pro-Q or Pro-Q 2, but it certainly gets the job done with plenty of room to spare.
Parametric EQ 2 is a great EQ, the frequency bars approach can clearly show individual harmonics. I use this EQ for all of my EQing. It's also great for modulation when creating basses.
My EQ plugin of choice, there are many better EQ plugins out there that are probably better than this but it gets the job done.