I use these for my phone at my desk at work with just one ear in, and when jogging. I listen to drum n bass, and generally and happy with them.   Not sure what is expected at this price point, it doesnt get much cheaper.

Yes, its worth it.   Galaxy S does have great sound, but other models also have the DAC. Nexus S, and some versions of Galaxy S III.   Other models like Galaxy Nexus, have a good DAC but perhaps not as good as Wolfson DAC.   Qualify headphones pretty much always help. Make sure you...