My experience too. I had switched back to 45 feet of Ethernet over the weekend and just switched back to fiber. Even with the two additional converter boxes (both with LPS) the slight effect was a very slight smoothing or taking an edge off but more to the positive than the negative and without losing detail or sparkle. Both sound good but I like the fiber just a touch better.
Folks, I think my use case might be completely different than yours. I am NOT talking about fiber through FMC vs direct copper. I am talking about the differences between the Fiber NIC vs JCAT Net NIC. This itself carries a lot of weight and sets the right context.

