I did the interview on Dec 14th, emailed CoRP back the same day, it arrived on Dec 18th.
Today I received CoRP signed. It says I became a PR on Dec 28th and it was sent on Jan 4th. I live in Toronto, the mail was sent to and received from Montreal.
Also, I successfully linked my wife's (she is secondary applicant on PR application) PR card application, but I couldn't link my PR card application. I hope that's only some error in their system since our online PR app still has "in progress" status and we became PRs.
Congrats to everyone on PR who received CoRP back, and those who haven't received yet read my congrats again in one-two days, because I believe everyone who did a phone interview in Dec will receive CoRP back to the end of the week.