I can't help it, but every time I have to eject a Garmin GPS from one of my Mac's, it take a long time, fails often if I eject with BaseCamp and I get irritated ;)
Even an Eject from the finder takes a long time. Now i sometimes just pull the cable, because every eject costs me 20-30 second.
I do switch often, most of the time for testing import's, routes, tracks.
It happens with the Edge800, Zumo660, Dakota20.
Please look into it to improve this in BaseCamp for Mac.