I recommend that you apply Online, because it is defiantly way faster (you can confirm this by calling CIC yourself and listen to the recorded message). According to them, paper applications take 115 days, and online ones take 32 days, we are talking about if you apply within Canada, so international applications take way way more of course. As you can see <== I applied in VFS paper based on June 8th and I already missed my Fall admission and still waiting until now.
The only help the VAC can offer is to double check the documents for you and make sure they are correct and complete, so if you don't need that I advise you to apply online...
Good luck