I'm really not sure about this name. Regardless of what the .com keyword sold for, I doubt this will have much of a reflection on your .us extrension, unless it became big and popular.
The 'Z' is also a bit of an input. It's nice though that you can use the 'Z' as a '2'.
I own CIY.us, and I know 'CIY' is a huge Christian based group, amoust other small things. I haven't been able to sell it yet, and I'm asking only a low price.