2nd yr AZCOM here. The basic sciences are great here. The profs are very very accessible and always have an open door policy. Boards? Sorry to say this but your step1 score is what you make it. No school is going to make you score higher passively. I'm in the thick of it right now, and it's all about personal discipline and time structuring.
Having said that. Medical education these days is an enormous bubble and it's going to pop someday, hard. I attend a school that seems to think they are immune to market economics and charge us top dollar tuition, meanwhile we see 1-2 new buildings being erected on campus in the last year for a new vet school, and new admin buildings. Also - there are many many acres of empty dirt flanking the current campus which if used would probably double the size of campus. So basically... it sure smells like the highest priorities are profiteering and expansionism, instead of being focused on providing some cost savings to students in these tough economic times.
tldr:
1) Azcom provides a great pre-clinical education.
2) Boards are what you make it, don't expect a school to boost your score. All about self discipline here.
3) Years 1-2 could be learned by anybody with books, videos, and enough discipline. As long as your school has a decent reputation, go for it.
4) Go where you have the least debt in the end. Medical schools are money making machines, avoid as much debt as possible.