Where is it imported from? If it's from Japan then expect to pay higher insurance and to have to run it on V-Power (or else risk engine damage), you do get more power though

. the key give away for a Jap import is a bolt-on foglight (or one cut into the bumper). If it's from Cyprus or somewhere like that and is full UK spec then you should be fine.
You should also look at the Spec.C Legacy. It's pretty similar (power is almost the same in the 3.0 non-turbo form, and the new 08 impreza is based on the current Legacy platform anyway) but more practical and doesn't suffer from the chav image of the Impreza.