paulcreed,
In my experience, people who feel that way about their systems usually have fundamental issues, and usually means bad room acoustics. Every time you move your speakers, you are changing the room frequency response as it relates to your listening position, quite possibly by a large amount, especially if you have limited or no room treatment.
Your brain becomes "accustomed" to your system, essentially trying to, at some level, correct the frequency response to what feels right. Technical term is neural adaptation. It is real, and you ignore it at your peril. You will frequently hear real acoustics experts discuss this. It is a learning process so it does not happen instantly. (There are other processes that occur more "real time" as well). You can both "learn" and forget ... hence when you come back to your "new" system after not listening for a week, things are magically better .... bass response is back, soundstage seems more "normal", dynamics are right. It is probably still not "perfect", but listen more and things fall into place (to a point).
Moving cables, if it makes any difference at all, is going to make difference at only the finest details, and things like dynamics, perceived bass response, soundstage, are not fine details, they are macro properties. If you continue believing that simply moving cables (with the exception of significant electrical interference) is going to significantly impact your system to the level you describe, then you are going to have a hard time ever being really happy.
Since you keep moving your speakers, let's get back to that fundamental problem. Your brain attempts to adapt, but can only do so much. Do you have a properly treated listening environment? If not, then that is something you need to address. There are great tools out there and cheap microphones, and a ton of information on how to setup a room. Once you get the hang of it, it is a heck of a lot more interesting and fun than swapping cables, and for the most part you won't be "guessing" ... was that better ... the results are often dramatic.