Equalizers- love them or hate them and why?

Like anything else, EQ's can be a + or a -....

Apply judiciously....*shrug*S*

Personally...I 'apply' 2; one in the 'puter,the other a 'stand alone' digital.  Either can be applied to primarily 'room correction' while the other can do monitor and measure on my 'DIY pursuits'....

Both are as flexible as I could care to use....been doing 'room eq' for 'bout 20+ years in this or some similar fashion...given the spaces I've had to 'play in', wouldn't think of 'being home without it'....;)

I use a Velodyne SMS - 1 to  apply low pass to my sub and EQ a nasty room mode centered around 40 hz

My amps can take just about any el34 or 6l6 variant so that's how I "EQ"  my speakers....  

My system doesn't have them, but I think most audiophiles around here who are unsatisfied with their sound would be better off with them.  If I ever buy and "end of life" system, it would probably include an Accuphase or Mac integrated with tone controls.  Plus, whenever I recommend an amplifier to a budding audiophile, I always recommend a Marantz or Cambridge with tone controls.  Just makes them happier. 

I have always used one.  Nowadays I use a vintage Kenwood graphic/parametric EQ, but only for recording.  I digitize vinyl and other analog sources.  I am mostly correcting frequency balance issues in the source material, source gear, and recorder (a Marantz pro-sumer CD recorder).  Easy-does-it is my rule.  My needle drops have gotten pretty positive comments when played at my local audio club meetings.