Okay... After a 4 year wait, I got my invite and my sim card 24 hours later. I bought my Nexus from T-Mobile. All I had to do was take the T-Mobile sim card out and put the Fi card in. When I got the invite I downloaded the Project Fi app before the sim card arrived.
Once the sim card was put in, the phone took control and walked me through everything (not much to go through).
I actually like my Google Voice number a lot, so I elected to go with that instead of my old number. Clean start, flush the callers I don't want to talk to (many). Let the others know my new number. I will port my old cell number to my VOIP provider.
Everything worked flawlessly. I was fully activated in about 20 minutes, even though the screen said it could take a day or two.
I live in Southeast FL and coverage is good. The quality of my calls was superb and former dead spots, T-Mobile always dropped, didn't drop. So it works!
Good news for you guys, who like me, were on the dead sea scroll wait list... Its worth the wait.