I live in the EU and ordered the O2 + SDAC but now see that it only has a US plug and the EU plug will either be $16+$26 shipping, or $23 in an EU store. For this price it will be around the same as the Fiio K5 Pro. I see that the Fiio has a stronger Amp but want to know if the Amp is better, the DAC is better and any other features which are better or different than the O2 + SDAC. Which will give me better sound?