I am with ABMP partialy because when I was a student it was cheaper and partialy because in phone contact they were much more pleasant and helpful they also offer more recourses for practice building such as a free website. just my preferance. nothing against AMTA
Before I entered massage school, I was with the IMA--International Massage Association (they have a branch for Reflexology) and received both liability insurance and business advice. Being new to the whole entrepreneurship experience, I appreciated the help.
When I entered MT school, I was told I could only choose between AMTA and ABMP for my liability insurance. They would not accept my IMA paperwork. So, after looking at both AMTA and ABMP, I chose ABMP. I liked how they were set up to help with your personal business. AMTA at the time (2002-2003) was good for education and continuing education. AMTA also was very political and exclusive. ABMP was just the opposite and met my personal needs. I am under the impression that over the years, that the exclusivity of AMTA has changed. AMTA also offers continuing education to members for reasonable fees. Each state has chapters and meets regularly to discuss issues. ABMP is not set up this way. However, they do offer free websites, business webinars, among other things. They also offer representation.
I am still with ABMP. I have recommended the company to other non-massage bodyworkers, as well as IMA group. Since working on the Massage Licensing Coalition, I have decided to join AMTA as a supporting member. I subscribe to AMTA's Massage Journal, ABMP's Massage & Bodywork Magazine, (also Massage Magazine and Massage Today). If you decide to join one or the other for your liablility insurance, etc., I recommend that you at least subscribe to the other's magazine. You'll make some great discoveries.
AMTA and ABMP are great organizations. I can't say that one is better than the other. The question is: What do you want out of your national organization? Keep researching. You'll find the organization that is right for you. :)