Applications aren't given any different priority if they're filed by a representative.
I'm sure you can get free help finding a job and getting help settling down after you land. You don't need to pay anyone for that.
If application filed by a representative does not a make difference in any aspect - then why do people retain a representative and how the representative justify its services
I would like to respond this post.
The value added of hiring a representative is the following:
1 you do not stress yourself on the filling documents
2 you do not have to be aware for mails or faxes incoming about your immigration stuff, the representative does this for you
3 using a representative decrease the chance of delaying because of back and forward failed documents (some of them just because a missing NA on any format...etc)
On the other hand, applying by you, will be cheaper since the cost of representatives may vary from 1500 to 2000 USD
Bottom line, the final decision always be yours
PD. I did use a very professional representative and I am already in Canada