I have had my 740 for several years now and have it mounted on a side mount to the winshield, Grumman winshield bowl, but in getting in and out have kicked it off the mount more times than I can count, and it always kept working after falling to the floor and yanking the power cord out in the process. The power plug finally failed yesterday, not in a good place, but that is a another matter. So it is going for repair. But if it could take years of removing and taking home plugging in at various locations and falling several feet with the power cord attached and yanked out I think it has nearly been inviincible and glad to get it repaired and change my harsh treatment.
Bill S