A few years old experience, but I had no issues, they just reitterated that I couldn't work while I was in as a visitor (I had previously been in on a work permit) and I was given the full 6 months visitor entrance. I've generally found Canadian border agents friendly and reasonable - be honest, have the right documentation etc. If your PR comes through while you are in Canada, you do have to leave Canada, and come back in on the PR (rather than visitor), which you can do by plane, or if you are near a border (Toronto, Vancouver, Montreal etc) just pop to the US for a day trip [btw, to avoid future problems don't have the US border agent stamp and send you straight back over the bridge - depending on the agent, this can be classed as a 'refusal' and will show up when you enter the US in the future - far easier to say you want to visit a restaurant / walk around the park, see the pretty falls from that side etc. and enter properly (in my case on a visa waiver) and then leave as normal! Just a caution, as I know a couple of people who get the 'are you SURE you haven't been refused question still, years later!]