The most important factor in soundstage imaging

The real question is which S.S. amp has the correct soundstage? Some depth and dimension are artifacts that exist in part to the fact that your speakers are set out in your room and also from the room itself. Many recordings with depth actually shouldnt have depth or at least have less depth than is presented. At least this has been my experience.  

Forgot to add that a real enemy of speakers are crossovers which is why single driver speakers, when kept within its frequency comfort zones, are so good. All crossovers are problems, even the best first-order ones. It truly is like polishing a turd.

@jsautter

Passive crossover add quite a lot of phase distortion. However, so can resonance from whizzer cones and the like. So not a black and white thing except that phase distortion from a crosssover can definitely be an imaging issue.

The perfect solution is a phase accurate active speaker from ATC. Active crossovers can maintain phase perfectly - no discontinuities in phase and therefore a minimum of phase distortion.

Time
Phase
Narrow minimum baffle
non resonant cabinet
minimize reflection back thru cone of magnet structure..
pistonic motion of the drivers in the relevant audio band love whizzers with 30% out of phase...( not )
breakup and or ringing far outside of the pass band
tuneable bass so you can fix room nodes, every room has MORE  than one, including the recording studio control room....
treat floor bounce in the critical midrange w tilt and a rug
treat first reflections agressively in the horizontal
natural mix of ramdom diffusion and absorbtion in a well lived in room ( give me a living room over most not all sterile, forest of amolifiers blocking the turntable “ audiophile “ rooms
get the equipmentbrack OFF to the side..
add Labrador  or any other working dog at your feet
good wine
.....have fun
enjoy the music....