One thing I certainly would agree with is that many who have them overuse them. I have a friend with a 54' sailboat that I swear cannot turn it without keying the thing, even when there is plenty of room.
People seem to forget they've got a rudder, can use spring lines, can use prop walk, the current, the wind...... And someday, the thruster will break. It will wait till you really need it. Like putting docking it at a boat show in a brisk side wind, with a large audience on the dock, a short handed crew.... Nothing like this has ever happened to me