Just had the H264 upgrade performed yesterday. Past mileage showed 201 when fully charged. This morning dash showed 264 but when I started it up, dropped down to 254. In any event, very happy with 25% increase.
After the upgrade you need to let the estimated mileage readjust to your driving habits and it will settle close to a consistent number. It takes a few weeks and a few recharges. Still I would continue to focus on the state of charge and the calculator in your head to estimate how much range you have left, especially on trips where you have deviated a lot from your daily routine.