Hello Robert,
We have decided to go to a single column layout rather than a 2 column layout. Why?
1. Single row means that there are more space to place info about the user and the actions as well
2. It works better in responsive mode.
3. Do not use a fixed height. If you have 2 columns layout, you need to have a fixed height and when there is some user info displayed on the user's list, this is problematic.