We did our medicals in advance back in June, so I'm not really sure how long it takes them to see it in the system.
I received an email 10 days after transfer to Detroit, (Oct 14) requesting RPRF, and the letter said they had the medicals, we sent the RPRF and some additional docs as well. 1 month after, we received the passport request. The letter says the visa will be issued in 10 days, but we went there in person, and got it on the same day.
The person at the front office said there is a chance that it will not be issued on the same day, remarking the 10 days on the letter, but she said she will check with the officers, we mentioned if that's the case we can't go back to Canada therefore, may apply for TRV, but in the end we didn't have any problems. So I am not perfectly sure if they always issue the visa on the same day. We went there at 8.30, they told us to come back at 11.30 to pick up confirmation of PR (required for landing) and the PR visa. Then on our way back to Toronto we landed at the Detroit border.
Another thing to remember, on the letter they gave us, there is a line that says from now on you can land at any CIC office nearby if you already live in Canada, and you need to make an appointment for it. I guess because of that if you don't make it clear that you want to proceed with landing at the border, they may just let you pass without landing, although we showed the COPRs and the PR visa and asked them what we should do, the officer said "that's it, you're good to go", we weren't sure what to do and called the CIC call center and then we found out that the earliest appointment is in 3 monthsand they said fastest landing is at the border, so we had to go back to border and land..
I hope this helps
