quote from road test...
The ride does a decent job of ironing out bumps and rough surfaces, although it can get caught out by deeper potholes, but it's impressively smooth on the motorway, so Subaru Outback comfort levels do impress.
**assuming yours is a Gen 4 (Gen5 legacy) either 2.0D or 2.5 petrol.... if it's rock hard something is amiss,,sounds like it's on coilovers !
mine's a 2007 and very compliant.
maybe get a Subaru dealer or Indy to take a look at it ?