passport request & Clearance urgent

[CIC]

Hi all,
I really don't understand everyone says after passport request they do security clearance and sometime will take maximum 7 to 8 months or sometime within a month , now My question is then how some people go personally and get visa in two weeks / week time like I was reading on London visa office and some other places as well, can someone explain  why some visa office take 6 to 7 months to hold passport and then issue the visa. thanks in advance.

[shibuya]

Just my opinion.

Some people do many things without informing V.O. and wait anxiously for PPR. Once the PP is sent across the V.O might find some travel made outside country of residence and especially if the applicant is a Muslim the V.O might think again to do a security check. SO here the delay starts.
I would suggest that whosoever keen to immigrate to Canada should reveal all relevant changes while the case is in PROCESS to avoid a longer waiting period after the PP is sent.
Any address change
Birth of a new born.
Change of job.
Visit to any country also if it is for 1 DAY  as they verify the entry and exit seals of immigration.