armrest extension opinions vary. I like the storage and the place to put my arm on long drives, but also noticed in hard driving I would tend to smash my elbow into it when shifting some times.
most people either really like the extension or do not like it. it is really a matter of preference. I would have to look at a new one to know for sure, but my old one in my 2005 was just two screws that would remove/install it.