I too do not believe in tweaking equalizers to suit my taste of music. Most of the time, I'll just leave the SQ enhancements to an external amp or a DAC connected to the source. No doubt source is important when we're looking at song bitrates and I wouldn't say that the SGSII suck as a PMP either. Currently, I'm playing FLAC music using PowerAmp with a personalized equalizer which produces sound quite similar to my desktop USB+DAC setup. All in all, it's the combination of earphone/headphone and the SGSII that makes the difference. In my case if I don't tweak the equalizer in PowerAmp, my high end IEM would sound like crap while other earphones might not need any tweaking to sound good at all. IMO, PowerAmp is a must have app for audio enthusiasts.
Just my thoughts.