Really, there's no difference.
Unless you've got a headset that works off more than 2.1 surround. I know of only a few that do, but these headsets will require 2, 3, up to I think even 6 (for 7.1 surround) jacks to be plugged into specific slots.
However, these kinds of headphones are less common, and usually only apply to people who know what they're getting into.
In terms of quality when using a standard 1/8th inch stereo jack, the quality will almost always be just as good in front as it is in back.
The only real exceptions are issues such as a loose or damaged wire, which can be present in the front, but are (almost) non-existent problems in the back I/O panel.