I love wagons/estates/Avants/Touring. There. I said it. I love them. They make so much more sense than SUVs but I love many of those too. My wife and I love our Audi A6 Avant and are very, very happy with it. She has already chosen to get it out of the house instead of me in the event of a house fire.
The only think better than our A6 Avant would be a RS6 Avant. The idea of a super fast wagons/estates/Avants/Touring is really cool so this E61 M5 is great. (Same opinion of the interior as others.) It's unfortunate the US has not embraced wagons/estates/Avants/Touring or else would have gotten M3 and M5 Touring models they had in Europe.