The stand/rack certainly has an impact on the sound. The question of which one will offer an improvement over what you have is the difficult part. If you are satisfied with the appearance and sound of your system you should leave things alone. I purchased a polycrystal rack to put my tubed gear on and it sucked the life right out of them. Conversely, I thought my solid state gear sounded better on the polycrystal rack so I put the tubed gear back on the room tunes rack. It is impossible to take something home just to try out and if you don't like it you're stuck.
