I bought the Microsoft Surface 3 bundle from Costco, and it arrived yesterday. Of course, I went through the setup process, which I found to be a good reminder that the Surface 3 is more computer than tablet. The most stunning thing were the number of updates to Windows that had to download and install, I don't think any other tablet that I set up required so many updates.
The bundle that I bought includes the 4 GB of RAM, 128 GB model Surface 3, the Type Cover, and Pen for about $100 cheaper than buying the each of the items separately. (Note that bundle is only available to Costco members.) There are two reasons why I bought the Surface 3, first is that I really find the integration with OneNote and the Pen useful, and second reason is that I believe I needed a newer computer for running Windows 8 and later this year Windows 10.
After following the initial setup that requires signing in using a Windows Live account, the next step was to pair the Pen. The pairing is done via Bluetooth and I think Bluetooth is used for communicating the button commands. There are three buttons on the pen, one at the top of the pen, similar to where you find the clicker on a ballpoint pen, and two on the sides. The top button provides the integration with OneNote, when you click it while the Surface 3 is unlocked, it launches OneNote. If you click the top button on the Pen when the Surface 3 is unlocked, OneNote launches and automatically creates a new note, ready for you to start writing.