Agree 100% with Zd's last paragraph in his last post. I have heard a few PrimaLuna pieces and thought they sounded terrific. Are there better? Perhaps, but you'll need to hear them to know them, and the differences will generally be subtle. I'd suggest you not worry about how the preamp stacks up to others and instead enjoy it, you have a fine unit and it works well in your system. You could spend a lot more money and not necessarily do better.
