When I bought Algorithmix Red, probably the most expensive EQ on the market several years ago, and one boasted about by Bob Katz (Mastering Engineer) as being the best EQ plug-in on the market next to his Weiss digital EQ units, I felt I invested in an EQ I though nobody could really ever beat. It was ugly in appearance, but for a Linear Phase EQ, it was the best one I'd used so far.
Now, if you buy Bob Katz latest Mastering book and look at the cover you'll be face-to-face with Equilibrium. Bob says good things about it inside the book, and the EQ costs about 10% of the Algo Red. Does this now make it a better
sounding EQ than Algorithmix Red? Not really, but it is far more flexible and is offered as a 64-Bit plug-in. The Algorithmix Red has all but been abandoned as a historical 32-bit EQ. But which sounds better? Hopefully neither, but the tool-set certainly wins hearts for Equillibrium. I bought Equillibrium because of the cool factor and it was on sale as a newly introduced plugin. However, I could easily get great results from EQuality, another DMG product.
I've also got a copy of AirEQ that's been mentioned here, as well as Waves LinEQ, and a few others. Which one do I choose? It depends. If I'm Mastering, I like the facilities and experience of EQuillibrium. For mixing, well, that's an entirely different animal. I just try different ones. Many times, I start with Waves API 550. If I can't quickly get a result I want, I may try an SSL G EQ or the SSL E-Channel. If it's a bass-prone instrument, I usually pull in a Pultec. For guitars, I may use a Helios. If I use a DMG EQ, many times it's just to notch something out, or to adjust the source material in a way that I don't introduce
character onto it. I typically use those types of EQ's to balance a signal out and then follow that up with a 'character' or 'emulation' EQ.
I was reading an old interview from Craig Leon, a classically trained composer who ironically produced the Ramones. In his workflow he tries very hard not to use EQ unless there's just no way. More and more I like to think that way when tracking, but in his opinion, when you try things, don't be afraid to do something wrong. It could be you end up with a result others are asking you to divulge. "I wanted to be the next George [Martin]. Be the next you, not the next somebody else."
All in all, my advice is to try everything you have! Don't worry about what you don't have and don't worry about which one is the best thing for a specific instrument or vocal. YOU be the judge and use what gives you the result you seek from your own emotions. What works for one may certainly not work for another. It's fun to see what plugins you barely ever touch can do, and perhaps how simple they can be! You may even be surprised that you DO in fact hear a difference between two or three different plugins!!