Hi K.! We lived in the Shen district before the kids made it to school. Supposedly they are award winning schools and we thought that was great, but after working with troubled youth I learned a few things about the high school I wasn't too impressed with. My biggest complaint with them as a parent is the size of the schools and classrooms. I heard recently that CP cannot develop any more unless new schools are built, due to the overcrowding. This may be a rumor but, sounds like it should be based in some truth since there are just so many kids on that campus.
I've heard parents in the Shen district say the kids get lost in the shuffle, they have to be EXCELLENT students to get recognition or awards, be college level to get on sports teams, etc. It sounds like alot of pressure for kids.
BH-BL is a small district with a close knit family. They would probably be your best bet. Ballston Spa is rearranging their curriculum last I read. I think that district struggles as well.
My oldest daughter attends Paige Elementary in the Schenectady City School District. Paige has earned rave reviews in the past few years and is know to be one, if not the, best Elementary school in this area. Schenectady also offers Universal Pre K, which is no cost Preschool, wish I knew that my first two years here! My youngest will attend Fulton Early Childhood Center in the fall. It is a brand new program in Schenectady that offers Pre K and K classes. Schenectady also offers Magnet schools, which offers specialized curriculums in several different fields. Another point you may want to think about is all day K vs. half day. These days, most kids go to Pre K or Nursery school, by the time K comes around, most are ready for the full day program. Shen still offers only half day I think. Not sure about the other two you mentioned.
All the school districts can be researched online as well. Hope you find this info useful!