We lived in the M Streets for several years and were in the same situation with our neighborhood school. I was extremely involved with the school and it finally burned me out. We moved to Plano about a month ago so my kids can go to a Blue Ribbon Exemplary school and I wont have to fight a losing battle with the administration. It took me 6 months to feel 100% about the choice we made. I just knew we couldn't stay where we were and be in a toxic environment. (By the way, there are some AWESOME schools in DISD, ours was not one of them.)
When I started looking, I used the district's websites and looked at accountability records, greatschools.net, and called and talked to the schools. We also wanted a great neighborhood, so we drove around in the attendance zones of the schools we were interested in and talked to the neighbors. We also were concerned about the feeder pattern. (in the old neighborhood the Middle school was not acceptable, but the High school was fine). We looked at the middle and high schools closely too. Thankfully, many of the neighbors we spoke to had lived there for 15+ years and had lots of experience with kids going all the way through. PISD has such a great reputation and it's more of a choice between the better and best. We feel great about our decision.
Good luck.
C.