ZSP the way to go
DONT EVER BUY A BMW WITHOUT ZSP ( ZEE SPORT PACKAGE??)
Jokes aside, I'm living this regret right now, it saps a good 15-20% of the joy out of owning my beautiful piece of German engineering... Why:
1. Sport seats. They are amazing practically cost as much as the car to buy from BMW as parts.
2. Sport steering wheel, smaller and fatter and more aggressive style. Miss out and you'll be spending $2K on all the parts required... my understanding is the rim wont swap with the standard airbag.
3. Sport tuned suspension: shocks, springs,anti roll bars to my knowledge.. Lower and stiffer. Not huge difference but a nice compliment to bigger wheels.
4. Tighter ratio steering? ( this was the case with E36 and E46 not sure about E90)
So basically its driving control and ergonomics. The wheels and suspension, sure, its not worth it if you're going to change them... BUT for the seats and steering wheel... Helzya its worth the $1500.
If anyone wants to sell thier old sports package components I'M BUYING!
Hope this helps.
Happiness IS the corner!