I like the full version of the Nomad Pultec EQ. It has both the high and low end section plus all the mid range section. The thing I like about it actually is in fact there are no visual cues at all. It is a real ears thing. If you know roughly where in the spectrum you want to make changes then you can jump right to the actual controls and provide either the boost or cut in that area. And even if you don't you will soon find out. Because turning those controls in the wrong area will give a bad or a no result and in the right area a very satisfying result.
I have used it in mastering too. It is great for clearing out the clug around 300 Hz or providing a little mid range bite too if its lacking. The top end of the Pultec sounds sweet too. Never seems to get that harshness that some EQ's can do.
If you do have it I do recommend running some pink noise into it and observing what you see on a spectrum analyser. Especially around the low end areas where you can boost and cut at the same time. They
don't completely cancel out but rather create an interesting shape around that area.
One thing too is don't use too much boost in an area for example. At first it can sound like nothing much has happened and you can tend to over do the boost only to realise later there is a
lot of boost there instead. It is like the boost sneaks up on you a bit. Use a little eg +3dB etc and listen to the mix or the track for a while. After a while you realise a lot has changed there!