Paola,
I would say that, if you already have all the documents (some of which can be expensive to get, considering translations, etc.), you should go ahead and submit your application. In the worst case scenario, the dreaded denial may occur and your fees will be reimbursed. It is time-consuming, yes, but you can send in the application and go on with your life as the process takes place.
If you have visited all the links offered by Immigration Canada, you know there is a page that shows you the estimated time the process will take for each major consulate/immigration office around the world.
Regarding an office being "moody", there are so many officers in each office, and so many offices around the world, that it would be difficult to establish a pattern. Also, how a file is treated internally is only known to each office, it would be difficult for us applicants to know what goes on inside the office.
A nice tool to track how the process goes for other applicants (and you may know this tool already) is the TrackIt website (
http://www.trackitt.com/). On that website, applicants enter their information, dates, timelines, etc., so that you can see what steps they go through and what they are actually required to do. The website also has forums where people can discuss different aspects of the application process.