I bought the GLE400 a few months ago. Incredible car. I agree that the v8 is insanely fast, but the biturbo v6 is also more than enough. It goes to 100 within 5.8 seconds, so not that big if a difference than the v8, but it is more economical. Even the 350 will be fine for most of the people, although I agree that you said it isn't fast enough. I am on normal suspension as air suspensions are not very reliable in general, no matter the brand and pricey to maintain. I thought it could be a mistake, but man it rides perfectly, especially on bad rodes, some say it is even better than the airmatic. And on the highway way doing 160 in a corner is not a problem. Only on very twisty road, you would feel more lean to the sides, but it makes you drive the car in a more relaxed manner, which I appreciate.
Thanks! I learned so much about this vehicle and your ex girlfriend 😁 I just bought one last week and it’s been great so far. I hope the previous owner wasn’t crazy so I can save money.