Just be sure to pick the right person. I've seen it where the AM, wanting to step down, actually picked an inactive member. Once that happens there is no way to "undo" the mistake except by going to support and begging them. They often do help, but why not avoid that problem? I recommend talking to the person first to insure they want the job, too. When I first joined my fs it went through about 3 AM's in a week as nobody wanted the job. Well, eventually somebody took it and did a pretty good job for a few months until RL took over and they then passed it on to me. That was about 5-6 years ago? So be careful who you pick as you might be stuck with them for the long haul.
AJ