Skimming through the price list, I did notice that the 65 has different upholstery and whatever. But you don't even get a reversing camera as standard on neither the 63 nor the 65. Not that it is a very big car to begin with, but still.
I hope this doesn't make me sound jelous, but I think the novelty of the G would wear off pretty fast as a daily driver. Maybe not the insane amount of power it makes, but the rest. It looked very cramped inside and I'm sure that more modern competitors with modern suspension both ride and drive a lot smoother.
I think I would start looking at Q7's and XC90's pretty fast. Then I would do the math and cry as I realized that my one year old G63 is worth less than a fully loaded XC90 T8 Inscription costs brand new.
Then again, you don't buy a G anything if you're after value for money.