Happy to inform everyone that we did our landing this weekend on Saturday at Rainbow bridge, Niagara, and got PR for my wife. For those whose spouse is here, this might be helpful.
The Landing was a smooth process. First step is to do flagpolling, i.e. to go to US border and tell them that you are there to do PR landing for Canada. they will give you a white form/ slip (that's called Administrative refusal, I guess) which you need to show/give to Canada side. This all just takes 5 mins. The Canada side people will check the COPR and Passport and will ask few questions and that's it, they approve PR.
Few things to Note -
1) Carry 50 cents which is required to cross the border by walk.
2) Carry address proof in case they ask, though we weren't asked for it
3) Go early in the morning if possible. We reached there at 8 and were the first people there for landing. others started arriving after us.
4) If you are going with your spouse, they might ask your presence as well. In our case, we dropped our spouses (I and one other fellow friend from this NDVO forum went together to do landing for our spouses) and went to Tim Horton's. But the Immigration people asked my wife to call me as she (officer) wanted to ask me some questions. I guess if an Applicant's PR has condition that the applicant must cohabit with spouse (sponsor) for 2 yrs after PR, then they might call spouse as well, to ask if you will be staying with your spouse for next 2 yrs. so I just said YES and that was it, PR approved.
Good luck to everyone waiting for their turn and congrats to those who have already got it.
