Most of them have not received this request. In the forum only 3 or 4 of them have mentioned they have received this request. No one knows for sure who gets picked for this and why.
1. It doesn't hurt to get one. It may not be necessary after all.
If you have it, you can upload it the same day you receive the request is made to you. However there is no special benefit for uploading it as soon as possible though. For those who submitted it the experience was that the submitted report is not immediately reviewed by CIC and no updates. Case seems to be kept in waiting. Some in forum argue that this could be perhaps all RCMP request from CIC comes with 60 days time limit to submit it and it may be possible that CIC is MAY be waiting this period to elapse before they proceed with the case. So it does not make a difference to the case whether you submit the requested documents the same day or 10 days later. FYI, we are told by RCMP that it may take 30 days to get the report. Most people get it in 7 business days at their home address by mail.
2. In calgary I did it at "Commisionaires". They charged me 58 CAD including tax. You have the option of getting the report submitted directly to CIC by RCMP or mail it to you and you would have to scan it and upload it thru MyCIC account. I prefered the second option because I wanted to make use of the newly enabled option to submit (upload) this RCMP report document in MyCIC account. Hope this helps.
If you haven't got your ITA yet and have this report ready, then you may submit it as part of "Additional documents" since RCMP report is not a required document. This way you MAY avoid the request itself been made effectively delaying your case. I'm not sure if anyone has done that way but its definitely worth it. All the best!!
We included RCMP criminal checks with our application. Since we were getting them from other countries and have lived in Canada for more than 6 months, we figured it couldn't hurt.