I honestly don't see the argument. I have 12MB/S service, and my WHOLE HOUSE is wireless, even to the network extender in the pole barn.
I see 11.7-11.8 MB/S pretty much at all times, including when the XBox is going and I'm downloading torrents in the background. Add in phones, laptops, netbooks, etc.
I know your service says "up to", but I honestly don't see it as a Gigabyte network when it truly isn't and you're paying for such. I'd just bitch them out, especially since your data is traveling the speed of light and still only 1/3 of what you're actually paying for