My wife and I had a 1998 E430 sport, great car, but decided to go with an SUV. It was either a Range Rover or a Benz. The Rover was a little out of our price range, so we went with the ML 55. If we were going to get an ML, I wanted the fast one. Gas mileage is about 18mpg, not great, but this is a very fun and cool SUV, not to mention it will spank every Rover I've seen. Fast, fun to drive, and I got slotted and cross drilled rotors and brake pads off ebay for $345 and only spent two hours doing them myself! No weak brakes on this ML! Will buy another when it gets 90k miles on it. Bought it with 52k miles and no regrets. Great SUV!
Red brembo brakes are a cinch to change, handling is precise, the awd system makes a nicely positive difference on wet pavement, good premium sound system, stable and safe. We also have a safe vehicle discount and pay less on this AMG than our 98 e430 for insurance.
If you want more upgrades than what this has, buy a newer one.