Vaio Z dock? Anyone care to share any experiences?

Hi all,

I'm in the market for a dock and I was wondering if anyone has the one from Sony for the Z (~$200).
The most appealing feature for me is the dual ethernet ports as I need to be connected to two separate LANs and I always have to remove one cable and put the other in.

Also is there any advantage to using the dedicated dock port beneath the laptop rather than getting a universal USB dock? (I found a really nice one from Lenovo that's $70.)

thanks