I made the switch from dji to gopro, waiting for it to arrive Tom.
I have both the Karma and a Mavic Pro.
I mainly care about the video quality which is why I typically only take the Karma out now. I take the mavic out mainly if I just want to fly a drone, or in the rare case where I am really tight for space with other camera equipment.
The Mavic is easier to fly (and overall better flying drone), especially for beginners and those that fly OOS that rely on sensors for obstacle avoidance. If you were like me and disabled it, then you will not see much of a difference flying between the two.
As far as any pointers, just ease into flying the drone at far distances especially if you relied on obstacle avoidance. Everything else, like a pre-flight checklist and checking flying conditions, should be the same as what you are used to