That's great if all you use are headphones. It may not be practical if you also use speakers.It's better to get a 3.5mm extension cord and use the rear port.
For example, I have speakers and headphones, and I want the soundcard to automatically mute the speakers and switch to headphone mode when I plug in my headphones, and automatically un-mute the speakers and switch back to 5.1 mode when I unplug the headphones. The only way to do that is to either plug in directly into the jack on the back (which I can't reach) or to use the front ports.
Assuming that your front ports are working correctly - that there are no grounding issues with the shared USB ports (and there are different ways to fix / get around that) - you're not missing much at all by using the front ports with efficient (low ohm impedance) headphones.
I assume that the control port that comes with the $150 Z card alleviates this situation, but we won't know for sure how exactly the control ports hooks up and functions until those cards become available for testing.