I see the big next step in audio performance coming from tailoring advanced DSP software for specific headphones and sources, and it's already here.
For example there is a company here in Sweden called Dirac who corrects some of the flaws in impulse and frequency response of the EarBuds and EarPods as well as compensating for the DAC and head out of the iPhone and iPad and the result is pretty damn impressive. It takes a pretty powerful processor to do this so it hasn't been a possibility with portable sources till the recently.
I'm confident this will be the big next thing with lower and mid priced headphones as these benefit more from the corrections. Not sure the SR-009 can benefit that much from impulse or frequency correction but you will be able to customize the sound much better than with DACs and amps. Like going from 95% to 99% of personally optimal sound compared to going from 20% to 70% with lower sets.
I can also see future software creating a perfectly natural binaural experience out of average stereo recordings.
I'm experimenting myself with different DSPs combining crossfeeds and soundstage and imaging enhancers, and they do a pretty decent job but are always in some way degrading the sound or not being fully realistic. It's still worth it with as some recording really go from in your head to fully out of your head, but there is big room for improvement for sure.
I've been using the Dirac app since it came out and use it 100% of the time when earpods are connected :)