I believe the point was that faster charging to allow more electric miles during the day is marginal if considering UPGRADE AFTER THE FACT. It is too bad Toyota did not just have 6.6KW OBC for all models.Depends on where you live. As of July 21, 2021, the cheapest Regular gas available in Sacramento, California, is $3.89, at Costco and Sam's Club. If you're not a member of either of those places, the cheapest regular at Arco and Fastrip is $4.01. The "name brand" stations, like Chevron, Union 76, Shell, and Exxon/Mobil are all charging $4.30 to $4.50/gallon. The overall average is about $4.25. Electricity in Sacramento costs 9.5¢/kW-hr between midnight and 06:00, if you arrange an EV charging discount from SMUD, our electric utility. So, let's compare on that basis. The Rav4 Prime in EV mode takes about 17 kW-hr to get a full charge from a 240v L2 charger - cost for that is $1.61, and the car can be driven about 43 miles in EV mode if the terrain is flat (it's a LOT less in hilly areas). So in EV mode, in summer, on flat terrain at 35 mph average on city streets, the car costs about 3.75¢/mile. At higher speeds, and in cold winter weather, the mileage and the battery capacity are about 10% less. Driving in Hybrid mode on gasoline, the car gets about 38 mpg. That's 425¢ worth of gasoline divided by 38 miles = 11.2¢/mile. Bottom line, if you live in California, where gas is crazy expensive, and electricity is cheap and EV charging is being subsidized by the utility company, it costs 3 times more to drive a Rav4 Prime on gasoline than it does on electricity. I don't call 300% a "marginal" difference.