Today's Sim's Delivery express?

Sorry for the odd questions I am about to ask but I haven't been keeping up with this particular 'new' way of updating the game. Now, are these considered to be updates and download if you're online and load the game? Do we have the option to ignore these? Is the new content optional and easily turned off? I have ignored every available update Maxis has released since August. Plus, I don't want to update my game unless a new pack I can't live without comes along. And why aren't the devs or gurus releasing any information about what we are getting? I've seen a few threads about this, but I am still very confused. Someone stated we would be able to choose what we want to download. Someone else said the opposite. And the gurus seem to be talking in circles about this. I have wanted to have a choice about ignoring certain updates for about three years, and if it's true the Express method will allow me to have more control over what is installed in my game, I am all for it. But before I do a happy dance over it, I would sure like to know what to expect.