Your L3 & DSHA-4 are really the two amps that brought out better "headstage" out of my HD800 & R10 and really make them to compete with the 007/009 for me. I agree with Steve that the K1000 has widest soundstage, but the Qualia is the best at depth cues and second at the width so it really enhance the illusion of being "there" despite its rather odd tonal balanced. Plus the K1000 is more of a stationary listening device....you really can't move around the house with those. I really enjoyed the Utopia when I had mine, but treble was a little much for me and I preferred just a little more headstage out of them. I really can't fault the Utopia on anything else...maybe on how heavy it is.
The HD800 SDR mod is actually the headphone that I use the most. It fits my lifestyle better for fraction of the price. It is my all around beater headphones. I toss it in my backpack and take it to work on a daily basis. It sounds great out of my mod Sony NW-ZX507 and glorious out of Doug ECP L3/DSHA-4.