For those on 2.7 you may see a propulsion system service error message, and I also got a coolant system service warning. Recently got these serviced at the dealership. Who confirmed the coolant was a tiny bit low and said that 2.8 corrects the propulsion error. They did not have 2.9 yet at the dealership. The errors were unrelated to one another apparently however.
Just passing along some info.
Have been on 2.7 since it came out OTA and otherwise it's been fine.
The errors did not affect driveability for me at least.