+1 UP!!
Poweramp is an excellent player, however an adjustable CrossFEED is one major "must-have" feature still missing.
Believe me. Once you've tried it, you cannot anymore listen to music through headphones without it, as it greatly reduces listening fatigue caused by the exaggerated stereo separation. Music produced to be listened to through speakers (i.e. pretty all music except some binaural mixes) sounds much more natural with a slight amount of crossfeed. This is the sole reason why I continue using foobar2000 despite its numerous shortcomings (no "double/triple click" headset commands to skip tracks, missing album arts can't be downloaded, unpleasant UI, custom skins not working on Android…).
A crossfeed feature would definitely turn Poweramp into the almighty killer of all Android music players! Please consider it.
Note to the developer: If you feel the BS2B implementation (like in Neutron) looks too complicated to be controlled with an easy UI (since you have to set the feed level AND the cut-off frequency of the underlying filter), please check the Meier version that only needs a single cursor/knob. Again, just have a look at foobar2000.