I can tell you the M35 is the ideal car for a family of 4 and long trips. The boot is massive, the rear seats have lots of room and the front is also very roomy. I also have an Outback and the M35 is far more comfortable and faster for long and short trips.
I went 1 step further and got the DVD headrests for the front seats and my kids have never been quieter on a 6 hour trip. I have cruise control on my car and I got great fuel economy on all my trips using the cruise (@117kmh indicated). I got 11.6L/100km on the way to Albury(loaded up with 2 bikes on the roof). On the way back got 11.8L/100 and then I went to Foster and got 11.2L/100 pulling a 7x4 high sided trailer. So economy is great.
Servicing is great and very simple and the 100k service is not that major as not timing belt to change.
As said before, go and drive them both and you will see what you can get.
If you can get down to Sydney, go have a look at the North Shore Prestige as he now also has the more recent M35's including the 3.5 NA stagea's.