Pkeller suggested trying the Heresys on their sides and so I did. To my taste I like the improved imaging very much. I noticed better detail and the Heresys disappear completely into a nice tight soundstage. I noticed, however, that off to the sides of the sweet spot the soundstange collapses and the music comes more directly from the speakers. This is very different from what I experienced with the upright set-up where the soundstage is still coherent even to the sides of the sweetspot but there is a loss of image detail. Holographic soundstaging, though missing image detail, is much better in upright position when off axis.
SO, my final conclusion. For most of the time when I am listening alone I will listen with the speakers sideways (tweeters in) and when I am sharing music time with a friend or friends the speakers will go back to upright (that is after they get to hear the sideways set-up in the sweet-spot just so I can see the look of wonder on their faces!).
YMMV and just for your own reference I am just coming off 6 months with Audio Physic Spark IIIs - talk about hyper edged imagery, holographic soundstage, and amazingly refined detail. The Sparks lacked a soul though which is why I came back to the Heresys. What they lack in detail and "refinement" they more than make up in sheer musicality and yes, "soul".