Approved for GE: Q2 2013
Applied for Nexus: March 8th, 2016
Conditional Approval: March 14th, 2016 (four business days after applying).
Interview & Approval: April 12th, 2016 (originally had one on April 5th but didn't end up traveling last week) @ YUL. I did try to ask if there were any cancellations yesterday (my arrival into Canada) and was told, no walk-ins.
The room is on the west side of the international arrival halls (you can use a compass on your phone, or alternatively, walk to the right after getting fully through Canadian customs - the outside sections near the airport are labeled A, B, C, D, etc... you want to walk down the alphabet). There's an overhead sign that will direct you to the room. It's locked at all times, just knock/ring the bell and then stand in front of the glass. Take a number and sit down. I used the short term parking (which is fairly expensive, topping out at $35 CAD a day - which I did while I was there
but it is a 1-4 minute walk from the terminal).
I was seen in a relatively timely fashion. When my number was called I handed over my conditional approval letter, appointment scheduling printout, passport, GE Card, drivers license, and supporting documentation (Canadian work permit). Told to sit back down. Get interviewed by CBSA. Since I was already approved for GE I guess they didn't ask me anything of substance - I was asked for the iris scan, and given a quick walkthrough of the program, then asked if I had any questions about the NEXUS. Sent back out to waiting room.
Few minutes later I was called in by US CBP. They took my documentation, asked me about primary purpose for travel, what I did for a living, and where I live. Fairly friendly and less questioning than my GE application from three years ago. They captured a new ID photo and took my fingerprints (I thought it odd since they already have them on file...) and sent me on my way. Approval email from GOES came about a half hour after I was done.
The CBP officer told me that my GE card is valid up until my NEXUS card arrives and is activated. I'm not sure about that given what I've read online, but it shouldn't matter since you don't use the GE cards at the airport kiosks and I don't plan on any land or sea border crossings in the near future.