We have been utilizing our C block licenses for nearly 2 years now using WaveIP gear. I still see the noise floor jump to -40 - -50 when the duction conditions are just right that brings in distant signals. We have a couple of licenses such as the one that covers Springfield MO that we cant touch because a local broadcaster is still there and they are still primary holders until the cut off date.
As you know the C block is channel 54 and 59 (I am not an engineer BTW). Channel 59 is Indianapolis' Fox station so until they pull their signal I am sitting on my hands.
I have been looking at SOMA for the cities I cover and Airspan for the more rural areas. How do you like your WaveIP product? I don't know much about them.