The lease is up on my 2010 528xi and I am awaiting delivery of my 328xi which should be here next week. I optioned mine as follows;
Sportline - I was getting leather and wanted the sport seats which I find give much better support than the standard seats, but did not need the external trim that the M package gives and used the difference in package price to get the lighting package. ( The better you can see the NY potholes,less chance of a bent rim.)
Cold Weather Package - On cold mornings the heated steering wheel and heated seats front and rear are worth it.
Navigation and moonroof - Navigation is convenient and included enhanced bluetooth and usb. I am a ragtop guy at heart so moonroof is as close as it gets.
As far as x drive vs rwd , my 528 xi with all seasons handled all the snow and ice we have had for the past 3 years. The real limiting factor is that the front spoiler starts to snowplow at about 8 -10 inches.
I use my car as my daily ride in and out of NYC (60 mi. round trip) and this setup is what works best for me.