I haven’t used Teamviewer before myself although I watched a friend fighting Teamview to deploy some fixes during CVWO, which doesn’t make a good first impression of the application =P. Hence much I have to say will be based on what team 7 said about Teamviewer.
3 Key Points raised by the team
1) Minimalistic UI makes the application less useable
Control surfaces on the remote desktop are not prominent and the functions of the icons can be confusing.
Designing a good design is hard. I would lean towards going for a clean UI rather than overwhelming users with a host of controls. However in doing so, some features may become less obvious and go undiscovered by users. Users might get frustrated if they cannot figure out how to get the functionalities they need.
The problem of unintuitive icons is probably compounded by the fact that Teamviewer was used on a tablet, where there can’t be tooltips to give users hints of what each icon is supposed to be. However, if their UI is consistent between the desktop and mobile applications, this shouldn’t be a problem for people who are already users of the desktop applications.
I don’t get the use case for Teamviewer on a tablet though, it’ll be simply too painful, especially if you do not have an external keyboard for your tablet.
2) Lack of quick start guide
Quick start guides are a good way to introduce less obvious features. However they cannot be counted on to remedy unintuitive UI. Most users will not have the patience or time to go through the quick start guide. It is quite likely that users will give up on an application that they have no idea how to use rather than turn to a quick start guide… unless there are no better alternatives.
3) Teamviewer as a means of playing games installed on your desktop on other devices
My observation of Teamviewer was that it suffers from rather high latency. Things might(should) have improved 3 years on but I have my doubts as to whether this can be pulled off well, especially for graphics-intensive games. The game’s graphics would be first rendered on the host computer before it is sent to the remote device. This likely translates to less responsive gameplay on the remote device.
Unfortunately, Teamviewer is not something I’ll likely use, especially not for the alternative use cases presented by the team. For file sharing between my devices, I’d very much prefer something that helps me sync the files automatically, like dropbox (which unfortunately does not have enough free space for my purposes anymore =/) or owncloud.