You ding dongs are talking about two different things. ACFAS is a educational organization. ABPM is certifying board. ABFAS and ABPM are analogous in that both are podiatry boards. ACFAS and ASPS are similar in that they are simply educational organizations.
In regards to the OPs question...it doesn't matter. At all. They are educational organizations. They are meaningless in terms of jobs, hospital privileges, insurance contracts, etc. Either the membership dues you pay are worth the services these organizations provide, or they aren't. For ACFAS its the conference and course discounts, CME, marketing materials, patient education materials, and the journal. ASPS is probably (someone can correct me if I'm wrong) part of your APMA dues, but they also offer courses, conferences, CME. I'm not sure about anything else they may offer or provide as part of your membership. You don't have to belong to either. You can belong to one or the other, or both. It doesn't matter.