Overall, Steam Big Picture Mode is beautifully usable. Its so well designed for a first effort it really showcases the huge difference between Valve and the traditional console makers: Nintendo, Microsoft and Sony. Sony just pushed a pretty large update to the Sony Online Marketplace and its better, but doesn't come close to the first version of Steam's Big Picture Mode.
What do you think of Steam Big Picture Mode? Does this seem like something you might find pretty easy to use or do you prefer the current console offerings?
Regardless, Steam's Big Picture Mode doesn't throw as many ads at your as XBox Live. Something I find pretty interesting considering you have to pay for XBox Live and have advertising thrown at you so prominently.

One minor correction-- you can make a free XBox Live silver account to access the store and such. However in order to play online with others (in most cases) you have to have a gold account. It would be nice if you could hide the ads with a gold account.
More importantly, though, Big Picture mode is amazing. I have used it for my main PC, not my living room PC, and I can even see benefits to it with a mouse and keyboard. I can't wait to see what, if anything, all of these new projects Valve is pursuing are leading up to.