So far so good.

Google Fi is currently offering $500 off Samsung Galaxy S23 phones so long as you port in a number and stay with Google Fi for just 120 days. No trade-in required; offer valid until sometime in January.

• Purchased three Galaxy S23 phones on December 9; instant $1500 discount; 256GB models, so $360 each plus tax
• Phones arrived about five days later (one phone was first projected not to arrive until January, but suddenly changed to a day later than the two other phones)
• Called T-Mobile to tell them I'm porting the numbers, and they gave me my account number and told me how to generate a Transfer PIN on the T-Mobile app
  • The Transfer PIN is only valid for exactly seven days (168 hours); if you don't get the porting completed within that time, you will need to request a new PIN
  • As an aside, and they can see we've been with them for 22 years, T-Mobile basically just said, "see ya later." Not even a hint of an attempt for retention.
• In order to port Miss Swede's number for two days after she gets back from college (in case things went sideways), I had to wait two days to request the Transfer PIN
• Baby Swede was the guinea pig; transferred data to her new phone, then installed the Google Fi app and initiated the porting request
• Eventually a notification popped up saying the port was successful, but there was an issue connecting to the Google Fi network and to contact support.
• While contacting support, I sent a text message to Baby Swede's number, and it was received. Closed the chat.
• The following night, I ported my phone number. Also got the same connection issue message. I waited a few minutes, and I was able to send/receive text messages.
• Last night, I migrated Mrs. Swede and Miss Swede (iPhone 15 user); Mrs. Swede also got the same connection issue notification, but cleared up within minutes.
• Miss Swede's seldomly-used Gmail account was locked out because it ran out of storage due to her using Google Photos (they were also being backed up to iCloud and OneDrive at the same time); once I cleared out enough space, it took multiple tries before the Google Fi invite was received
• I followed the instructions on Google Fi's website to install the new eSIM on her phone, she manually updated the network properties as direct, and all she had to do was reboot her phone to get service.
• Today, I confirmed with T-Mobile that my account was cancelled (which happens as soon as all numbers in the account are ported out).

Reception has been pretty much the same since they use the same T-Mobile towers. My only frustration is that I'm in the middle of a 1/2-mile area where service is just awful for all cell phone carriers. About a mile west of my house, I'm getting almost 500mbps download speeds; at my house, 3mbps on a good day.

If the service truly sucks, I can become a free agent again in 120 days (180 days if I want to go back to T-Mobile).