Schools, like many other things are viewed subjectively. The test scores are probably the most reliable indicators of performance and trends. The bottom line is that each situation is unique and what works for you may not for other parents. If you have concerns, hit the bookstore and get a few grade appropriate workbooks for the kids - see how they do with material outside of the class. Obviously keep in contact with their teachers as they will best alert you to any issues - and stay involved with the kids and their work.