hello! My daughter is in K1 at SAIS. She just started this term, and we've had a good experience so far. My daughter likes her teachers, enjoys her work, has made friends easily and seems happy to go to school. Thank goodness!
The school is small, but the facilities are great -- especially considering it's a foundation campus. There was some talk on this board about the fact that it didn't have a pool. They just added one. They also have a basketball court, mini-American football field and a soccer field. There's also, of course, great playgrounds for the younger kids. There's also a temporary outdoor "ice" rink made of artificial ice (some type of plastic that requires no refrigeration). Not sure what the long-term plans are for it though. The families are really involved and extremely welcoming, which has been great for me too. Feel free to ask me any specific questions you may have...
I don't know a lot about SAS, but the families I know with children there seem happy with their choice.
Good luck with your school search!