Pro is basically that you as site owner could be covered by a $2.5 mil liability policy to cover your butt if you are sued as result of actions by club members and guest flyers that you allow to use your property. Of course that isn't a 'pro' argument in and of itself. It is just an offset to the risk exposure to your fiscal well being that you will take on if you open up the use of your property to others. The real pro side has to come from your personal motivations, e.g., camaraderie with others sharing like interests, a service to the community, etc. Can't comment on that as you have not said anything about why you are considering doing it.

Con is that AMA mandates all chartered club members and guest flyers must be AMA members. That may cramp your style if you want to retain control over who may use your property to fly a model airplane. AMA members ONLY, and that exclusivity applies to you, family members, and guests. AMA provided insurance won't cover you as site owner for liability resulting from the actions of a non-AMA member. Again, can't really know if that is a downside without knowing anything about what is motivating you to consider an AMA charter.

Tell us what you want/expect to gain from an AMA charter and you'll much more likely get the kind of answers that will help you arrive a decision.

Abel