Both Sherbourne and Compass are fine schools, but usually they are second choices of expat families who could not find spaces at DESS, Doha College or ASD (these schools are more established and have better facilities, and Compass and Sherbourne are for-profit schools, which means not all of the fees are invested back into the school). I have known several families at Compass who chose to stay even when spaces at these schools opened up, because they were happy with the school. The waiting lists for the places like DESS and ASD are long, and most families wait a year or more. It is best to put in an application on the first day they open up the process (in the autumn, but phone to find out the day). Even if you are happy with Compass or Sherbourne by then, it is best to have a choice.

Good luck!