I just purchased a Wyred4Sound SX1000 and preamp - maybe have ten hours on them. They are much superior to my old Krell S300i with 300 hours on it.
The W4S do not sound materially different overall, but there is certainly much more detail, much more width, and much more depth.
There sound is more palpable and that makes it feel more live.
It will be interesting to hear the improvement after another 100 hours.