Looking at your past rides, make sure you take an extended test drive in the RWD 535 to be sure you can live with the steering feel. Even though you may never see snow, you may want to consider an xDrive for the better steering feel (though even that will feel awfully light compared to your Z4 and M3).
BTW I agree with others that you should have Tech/Nav, PDC and rear view camera (we never use the side view or birds eye view) and BMW Apps. Our 535 has soft-close doors, lane departure warning, blind spot detection and auto high beams, and I find them all to be a waste of money.
2011 535xi M Sport
TiAg / Black, ZPP, ZP2, ZCV, ZCW, ZDA, 2TB, 6NR, 465, 5DL, and a Partridge in a Pear Tree
2011 X5 35D
Deep Sea Blue / Oyster, PP, SP, PSP, CWP, Tech, 20" 214's
2008 ///M3 Vert
2008 X5 3.0
2007 X5 3.0
2006 X5 3.0
2006 550iA SP
2003 540iA M-Sport