I use RealVNC within my organization for multiple tasks. It's a quick and easy way to remote into a users PC and resolve an issue. We also use it to remote into servers at sites all across the US and in other countries. Since RealVNC has an easy to use interface, it's very quick to pick it up and use it when needed.
RealVNC offers a more intuitive user interface and feel than Remote Desktop. It navigates authentication quicker and easier and provides easy to understand feedback if you're having an issue connecting to a host.
I chose a 10 because of it's easy of use and small client size. It's easily installed / deployed and works pretty much right out of the box. It's well suited for machines that are on the network, either physically connected or connected through VPN of some sort. RealVNC can also work using IP of machines outside the network, but functions at it's best with machines on the same domain.
The training is very informative, quick and to the point. All of the details one would need are present so the user doesn't have to go searching for additional information just to use the application. The layout of the training was also neat and concise, some of the other training sessions for other companies I've done in the past were confusing and not well thought out, this one is much more superior.