The most important thing you need to know about Walton County is that it is 2 counties in one, with the power and leadership of both the county and the school system concentrated on the north end of the county. Also, the school system is entrenched in politics and a pretty significant good old boy system, so things aren't perfect here. Hopefully the superintendent referendum to change to a hired superintendent will pass and will start the process of a more cohesive, forward-looking district. Yes, we have good test scores, but what does that really mean?
However, I can say with a lot of confidence that your child will have a good experience at any school in South Walton, if you are an involved parent. This holds true for any school system, not just here. (I am not familiar with the North Walton schools, so I can't comment) There are some exceptions and families who have had bad experiences, but again, that happens in every school system. There are also choices here for high school which is nice- AP and dual enrollment at South Walton, dual enrollment (Collegiate High School) at Seacoast, Florida Virtual School, Niceville (Okaloosa County), Arnold (Bay County). It all depends on what you want for your kid- college prep, AA degree in high school, good sports programs, lots of extracurriculars, etc. Bottom line- get involved in the school AND the community.
Regarding ECMS- it is a great middle school with dedicated and hard working teachers, all the sports, and all the extra curriculars. My daughter will be a 7th grader there in the fall. My son graduated from SWHS in 2011, but I have friends who have kids there who are thriving and excelling, busy with academics, sports, and clubs. They are also reporting that Dr. Tibbetts seems to have the correct vision for this school- that there is no reason why it can't be one of the top schools in the panhandle.