I've had a diesel Outback since April 2008 which as far as the engine is concerned is the same as the Forester. The engine is superb, tows 1400kg's of Adria fine and has really respectable fuel economy - even when towing and never getting beyond forth gear (might be better with the 6 speed box on the new Outback and Forester.
The clutch is an art when towing, takes time to learn avoiding massive slippage when getting on-board Portsmouth ferries. Don't expect to reverse a van too far up any gradient without getting a very nasty burning smell, fortunately only had to do this once on a tricky pitch. Of course this maybe my relative inexperience having only towed for 1 year.
As for general driving, you can't fault the Subaru build quality and AWD system, the winter weather this Jan proved it's virtually unstoppable.
The one great comment I always get, is from passengers who have never been in the car before - they're all surprised when I tell them it's a diesel - it really is that quiet when warmed up!
If you want a seriously reliable, quiet and comfortable car with reasonable towing abilities, then you can't go wrong with a Subaru diesel - even if people mistake the bonnet scoop for something that should be mush faster!