I study in Doha British School, and i can personally tell you that it is an amazing school, with a very good standard of english and other subjects...
almost every child there can speak excellent english, the teachers are very supportive, the classrooms are well-equipped, the way of teaching is amazing...
i am not sure about how they give homework in the primary section since i'm in year 8, but we have this tic-tac-toe system for homework, here is how it works:
we're given 3 main taks per term (we have 3 terms each academic year, for the first and the secong task, we can choose which one we want to do from 4 tasks but we don't have any choice in the third one and it is considered the most important one.
I would definitely recommend Doha British School and i hope you get what's best for you :)

you may ask any more questions from me, i'd be happy to answer...