Before I begin, just know that I'm still in the app cycle and have received a few acceptances, with AZCOM being my top choice. Also, I'm not from AZ.
I picked AZCOM because of the competitive match list and the positive interview day experience I had. There wasn't much to go off for this decision other than location, curriculum, match list, and other things I've heard through word of mouth. I think Glendale is a prime location, not too far from popular cities (Scottsdale, Phoenix) and nature but not dead in the center of it all either so you can live and study in peace. Curriculum wise, I've heard that it is quite strenuous and involves frequent testing, but I'm all for it if it's going to help me do better on boards. I will definitely need to get used to it once school begins. For match list, students here seem to match into prestigious residencies and specialize more than many of the other DOs, but I'm sure this also has to do with the rigorous curriculum and preparation. My guess would also be that some of the expensive tuition goes towards developing the program and making connections which works in the students favor for residency. Finally, I've also heard that MWU itself has a prestigious name and is pretty well established. Thinking more about it, the thing that sets DO and MD schools apart other than the core principles is that MDs have been around longer. This gives MDs the advantage of having more connections and resources. Even though DOs and MDs are both great doctors, DO students probably have to work a bit more to match into a competitive residency, although this seems to be narrowing. MWU itself has been around for quite a long time(1900, 1995; yes, there are other DOs even older) thus it probably has quite a few resources. It also gives off this impression if you look at the campus (size and quality) and compare it to some of the other DOs. Again, I don't think there is a real ranking for DO schools, so there is no real way of knowing which school is better, but this is just my two cents after doing some research. Try to find things that cater to you when deciding schools.
If there are any AZCOM alumni or students who can comment/confirm this, please do so!