I understand that North Point (am) will move later to another site. The current site will be used by North Point (pm). This is probably in 2 years' time.
Comparing the 2 schools, Hennessy Road campus is actually in a better condition than North Point. I am not biased but I have visited both schools and have been inside the classrooms/toilets etc.
Another thing to consider - by the time your son gets to P1, Hennessy Road might lose its connection to QC. Talks are flying around but of course there is no confirmation. So it is a chance to take!