It depends on whether the amp is burly enough to be 6 ohm stable. As Russ mentioned, if it isn't the only thing that the 6 ohm setting does is to enable protection circuits that keep the amp from overheating so in that scenario you actually get less power to the speakers.
With a 130 wpc Elite I would think that it should have no trouble dishing out enough power, so I would recommend the 6 ohm setting, but you might experiment with both to see what difference you notice.
If you have a chance to let us know your findings that would be appreciated, thanks!
Jason Hicks
Aperion Audio Guru