Most digital equalizers use the same math

Forgetting for a moment the special cases that set out to model analog non-linearities, nearly all digital equalizers are capable of identical results if tweaked to match curves.  So why choose to use one over another?  

Because ergonomics matter.  

The eq that gets the best results fastest wins.  Not only because it saves time, but because it gets to the target while the first impression of what the user set out to accomplish is still vivid, without confusing detours into unexpected results.