Mapman, if you're not hearing glare or haze and you can listen for hours on end, then you've got a fine setup. The fact that a small move of the speakers made a significant difference to you tells me that you're really tuned into small distortions. If those are removed, then a system change can make things sound "different" but it becomes agureable if they're "better." That's for you to decide. I think you've gone about this logically and reached an appropriate conclusion.
Dave
Dave