These two schools are the opposite of the spectrum - RC is very traditional and HKUGA is activity-based. If your child is active, HKUGA may be more suitable; if your child can sit still for long, RC may be a good choice. Both seem to have a reasonably good academic standard.
Oh? Why don't they call candidates on waiting list knowing how many have given up their places after registration? Why do they wait so long to call?
Maybe they want to wait until the lucky draw results are announced so that the drop-out list will be complete by that time. This prolongs the waiting time for parents though...not nice.