Yeah I got tons of details. When I was car shopping a few months ago and looking to trade in my Z, the 550i was waaay high on my list. It was that or the M56S. I went to a number of BMW dealers, drove the car and walked away really disappointed. The steering feels artificial, for starters. It's not quite Audi bad, but it just wasn't what I was used to coming from owning a 335i Coupe and driving my brothers E62 M6 on a frequent basis - both cars with incredibly tight steering setups.
But I hoped the chassis would feel better, and it didn't. Lane changes caused an incredible amount of sway, the body roll was extremely evident and the front and rear of the car simply felt disconnected if you tossed the car side to side. You could feel the rear move after the front, this is usually a sign of very poor damper control, soft sway bars, and spring rates that are geared more for couch-highway cruising, rather than GT sportiness that the 5-series had been known for in the past. Not even the current Audi A6 is that poorly sprung. So imagine this car through a sweeping turn or exit ramp...and ti just didn't feel pretty.
The worst though was when you peg it on the highway and you could feel that open diff doing its worse, where the car actually moves toward one direction as one wheel spins faster than the other...there is simply no excuse for this in a 420HP+ high-powered sedan. On a barely slick road, that was simply infuriating. I tried looking at M-Sport models, but then I was stepping into a territory of money I couldn't justify and apparently it doesn't even help that much anyway according to everyone who owns them or has driven them. The car mags even back this up.
None of this should come as a surprise, because the 5-series platform is based on the 7-series platform this generation.
