I have a single mount for my phone/battery monitor. Been using it mostly for phone so ordered another for my battery monitor and will have them both off the behind the dash anchor for the LR3. There is a bit of wiggle off road but not enough to cause an issue for me, will see how the second arm does soon for a trip to Moab area.
Really like the gripper for the devices. Easy in/out.
edit: Been on several off road trips since install and the two mounts are working very well.