Sure you should apply online since it saves time (by at least a week).
However, applying on line DOES NOT mean your application is processed with the speed of those inside Canada. It will still take roughly the time frame taken at the embassy which caters you i.e. your country of citizenship or current residence.
In rare cases, online applications are passed to other visa offices to balance work load but that is transparent to applicants and is the rare exception.
Another important benefit of online application is that if any thing is missing you get to know pretty much immediately and can address that. For paper based submissions often you waste months only to get to know that your application was missing document x, and is being returned unprocessed.
Lastly at least in my country, for paper based submissions, most of original docs are required. Instead for online case, you got to keep most of originals with yourself and would only require passport in original when needed. That reduces the risk of losing docs (trust me i have seen several such cases with embassy bearing no liability).