Surpised to hear that!

Take it the car is a manual - known issue with the 1st to 2nd gear change - removing the Clutch Delay Valve might help.
The 2.2l in manual is just about enough for a car the size of a 5er. Ive a 2.5 Auto in mine, and its not amazing, but grand for what I need.
The radio is noise sensitive, so a higher speeds it raises in volume to overcome road noise....neat feature if you ask me. Having said that, sometimes if someone lowers the radio using the knob it shoots up in volume initally, but then goes down, but not a major issue, as its normally controlled on the steering wheel.

One thing I find in the 5er is that the perception of speed is a lot different...you dont feel like you are going fast. I travel to work early in the morings, and tipping along thinking in my mind that Im doing approx 70mph, Im in fact doing a lot more as Ive no other moving traffic to reference the speed.
A car that size, unless its an M is never going to blow you away...they are built to be motorway munchers.

Have you driven anything for a reasonable trip since buying the car....as any time I had to driver her Almera, I'd be damn glad getting back in the 5!