Don't be sorry for ranting! One man's rant is another man's helpful information... Anyway, I totally feel for you - I am in essentially the same position, only waiting less time so far. I have a very strong feeling I will be going beyond 15 months, particularly because CIC so nicely decided to ask for my additional PCCs near the END of my 12 month schedule.
From what I know about the background check process, the amount of time it takes really depends on the other countries you've lived in or traveled to; some countries are very slow at replying to request for confirmation/info, in addition to the fact that the different agencies that take part in conducting the background check look very deeply into all of your activity, at home and abroad. There is a lot that factors into processing time when you've traveled or lived elsewhere.. I know my passport is full of visas and the amount of checking they need to do is probably making their heads spin!
The unfortunate thing is that CIC is so useless when asking for information, and even going through an MP or ordering GCMS doesn't seem to give you much detail about what exactly they are doing with your background check.
Maybe I'm wrong about all of this, but if anyone else who has traveled a lot or lived elsewhere has had a quick processing time - I'd like to hear from you!!