St. Andrews A990 Program - Is it worth it?

I have recently applied to the A990 program as a grade 12 highschool student in Ontario. I am hoping to get the opinion of a recent A990 graduate on how good the program really is since I've heard and read a lot about graduates not getting residency after the 6 years. Do you really think it's worth going? What is the likelihood that I'll actually get residency after graduating, whether that be in Canada or the UK or someplace else? To anyone that is in or has graduated from the program, what are your thoughts on it?