I just noticed that there was a new firmware update (V4.01) for the X180/160 and was curious if anyone had installed it yet.

Yes installed it and all working fine, it's only a small change for focus:

"Ver4.01 (Functionally, it is the same as the Ver.4.00.)
1. The rare case that focus function cannot work is supported."

I have also purchased the Sony MCX-500 Vision Mixer and I am fairly impressed with it's size and functionality for live events I record. Waiting for the Sony RM-30BP to allow remote CCU-like control of up to 3 cameras (X160/X180 now support on firmware 4.0)!