Nice car, but sadly it doesn't fare very well on emissions, fuel economy and depreciation when compared to the 535i.
Just for comparison:
BMW 535i SE Auto
-MPG: 33
-CO2 Emissions: 195 g/km
-Road Tax Band: J
--6 months: £129.25
---12 months: £235.00
----First year: £425.00
-Value retained (3yrs/36000 miles): 42%
Saab 9-5 Aero 2.8T XWD Auto:
-MPG: 26
-CO2 Emissions: 244 g/km
-Road Tax Band: L
--6 months: £233.75
---12 months: £425.00
----First year: £750.00
-Value retained (3yrs/36000 miles): 32%
The Saab is cheaper to insure, though. Unfortunately, the new 9-5 Aero 2.8T costs £38k, which puts it right in the £38.600 535i firing line. Oh dear...