NW Austin is considered more of a region than a location. To the east will be Manor ISD (Travis County). To the North (Williamson County) will be Round Rock ISD and Pflugerville ISD. West area
is Lakeway School District.
There can be homes in one city area that have a school district in different city area. For details
on Schools and ratings guides, go to any local title company website. There will also be School District boundary maps.
Here are some website names.
Paul Puig, Keller Williams Realty
Travis, Bastrop, Williamson, Hays Counties
However, your question is about "Northwest Austin" which is a rather large geographic area and served by three separate school districts, AISD (Austin), RRISD(Round Rock), and LISD(Leander).
As mentioned before, the school ratings help most people decide. Some excellent schools are available in that area, and you wouldn't get much argument from anyone regarding Spicewood Elementary (RRISD), Laurel Mountain (RRISD) and Doss (AISD.)
I am available to help you with anything related to Real Estate, especially Northwest Austin area, as that's where I live.
GRI, CRS, ABR, CLHMS, e-Pro
Exemplary is the top ranking the state will give a school, so those may be the "best." However, some schools may offer special programs that are important to you. Those have to be researched on a case by case basis. If I can be of further assistance, please let me know.
Austin Home Shop Team