I do not have a child in the school district, but I will tell you what I've heard from other moms who have really researched the school districts special needs programs for autistic children.
Lovejoy is a great school district, for "normal" children. They do not have a very good special needs program, as they are not large enough to have the resourses that other districts like Plano have. Their emphasis is, sadly for children in the autism spectrum, about high academics and excellence for their general population.
Honestly, I really wanted to be in the Lovejoy ISD. My older son is on the spectrum (very slight), so when I started asking around and inquiring about their programs, I learned that Lovejoy's is not one of the better one's around. I really trust my last source on this. It is a friend who moved to a school district in Dallas (I think Highland Park, but not sure) for their PPCD program, and plans to move to the Lewisville/Flower Mound area when her son reaches grade school age. She is very active in the the autism community and had done TONS of research on the subject.
We are in the McKinney ISD, but currently send our son to a private school. Our son kindof falls through the cracks. He is different enough that school (especially socialization and large crowds) is difficult for him, but not severe enough that they will help him. It is so frustrating!!! The school we have him in is NOT a special needs school, but he has blossomed in the small classroom and loving (but structured and disciplined) environment.
Good luck, I know it is such a challenge to know what is right for a child on the spectrum.