You can compare the general policies of both schools, but you can’t generalise by saying that one is better than the other. Beaconhouse and TCS have many branches; some are good, while others are bad. Some TCS branches are probably better than some BSS branches, and vice versa.
I graduated from Beaconhouse Garden Town, Lahore. I would rate my experience 9/10. The only reason I deducted a point is that the school lacked air conditioning. However, I cannot say the same for other BSS branches, and I’m pretty sure that LGS and City have their own branches that are just as good, if not better.
Also, I feel that schools should not be converted into status symbols. I don’t advertise the fact that I attended BSS, and I don’t need to. Send your kids to BSS or TCS or LGS, but teach them to be very humble.