I've driven all three. Get the ML63 if you want to go fast in a straight-line. Get the E70 4.8i if you want to go slower than the MB in a straight-line, but much faster in turns. Wait for the E70 __is model if you want to go faster in both a straight-line and the turns.

The E70's new front suspension geometry can't be touched. Every race car uses a double-wishbonse suspension like the because it yields the best possible camber curve and has less stiction than a strut type system. =better handling and grip, with less ride harshness. This geometry works very well upfront (like the E70) in fwd and awd cars.

Imo, if you want the power and the handling, and can't wait, you should be looking at a Cayenne Turbo. Almost every product by MB is substandard in terms of engineering and quality; it's kind of like the Big 3, but German.