I have a gigabit network, mostly.
My core has a Broadcom gigabit ethernet adapter it is hooked to a Trendnet http://www.newegg.com/Product/Product.aspx?Item=N82E16833156211
Gigabit switch. Very inexpensive. Like $38, and newegg free shipping
My Living Room MD is currently only connected at 100MB, it is a 10/100 onboard nic.
My laptop MD has a Intel gigabit, and boots almost in half the time that the living room MD does.
I intend to add a new Intel gigabit card to the Living Room MD and am scoping this http://www.newegg.com/Product/Product.aspx?Item=N82E16833106006
at also under $40. And I can utilize the slot on my inadequately slotted mobo.
But I am all for Gigabit Networking.