I eq mine because I don't tend to use my better cans in favor of cheaper earbuds that I don't mind getting lost or having coffee accidents - those definitely benefit from just about any eq. I don't think Beats sucks as much as it just is what it is - I agree that it seems to have that charactistic loudness eq, but I could almost swear that it also adds a very slight reverb as well.
Anyway, if you're rooted, go for DSP Manager (see our root sticky), and if using that or any other enhancement, turn off enhancements in the system sound settings so you don't have the two butting heads.
Equalization can be used to give favorable colorations to the music or to help remove colorations suffered by the end-to-end hardward (dsp, op-amp, headphones/speakers). I don't think that there's a wrong way about it, although I tend to prefer and promote the latter.