At present, I only have a Lumin T2, But I did upgrade to an SBooster power supply and after about a year I upgraded the stock fuse to a Synergistic Master fuse. I ran it for about 200 hours for break-in and then I flipped it the other direction. Then I heard the sound I was hoping for. The soundstage was much improved in both separation and depth.
I am toying with upgrading to the X1. It will indeed get a Master fuse installed.