I think my E70 is WAY more refined in every way compared to my E53. I had 20's on the E53 and the ride was firm and solid. It took some effort to turn and keep the vehicle straight especially on warped roads. The E70 has even bigger 21" wheels and requires no effort at all. I have the dynamic handling pkg which is more of a sporty ride but still smooth and very responsive. The active steering makes all the difference too. The exhaust note is what sold me on the new 4.8! When I took it for a test drive, I had to have it!
As for the X5M, it is even better than the new 4.8 in every way. You have to drive it to feel it. Much more responsive steering and handling. Completely feels like a different car! Smooth, powerful and solid!
As for your 4.8, I see you have it lowered AND you have the 21" bigger wheels with runflats...and you're wondering why it's not smooth over bumps??
