Hi James,
Actually I find preamps with lower output impedances work better as the ratio works in my favor.
For example, a friend has a Hegel H30 with a lower than usual input impedance and his C500T works beautifully. I love my 28's and think, for my taste, the C500T or new C1100T could be a great match as well.
I plan on keeping them until well past the warranty period
They truly are a home run.
Right now, I am going direct to the amps from my Lampizator Golden Gate. A simple and stunning system, IMO. I have all my other gear off to the side in my room. I feel no need to hook anything else back up. VERY unusual for me.