Device type doesn't matter when deciding which one to set up as AP and which one client. It's the amount of interference each can suffer and the one with more interference should be configured as AP. Most of vital tasks (such as channel selection, flow control, etc) is performed by AP, client just follows AP. So it's AP which should "see more of surrounding world" to make more qualified decissions.
Well for me to manage PtP's at a very remote location, the decision is based on my remote connection to the network. As the client follows the AP in many settings, I want the AP at my "remote connected" side of the link. Changing channels and setting DFS channel lists is on the always reachable side, and as the client side is set to "nv2 nstreme 802.11" mode, switching between modes is easy, ... the AP selects and the client follows. The possible reason for turnaround of the roles are "radar detects" and in my case avoiding "false positive radar detects", which trigger the 1-minute DFS radar detect interruptions.
60GHz is now on my shopping list with the Cube 60G ac and its 5 GHz fallback but for shorter distances (<500m, marketing numbers are always optimistic). High in the mountains there is quite some bad weather and snowfall.