I have a 400 EXC and a 640 Adventure. I would trade both of them, in a second, for the 525 Dakar race bike (pictured in this thread) built by Charlie and his gang of 'Riff Raff'. I have dropped and abused all of my bikes and am always surprised at how well they hold up. I am the one who seems to break. Shoulders, ankles, ribs, etc. KTM makes great motorcycles that work! The key, in my opinion, is selecting the lightest and smallest displacement one in their line that works the best for your needs. I seem to spend more time on my 200 EXC than any of them. I can ride longer and faster in more difficult terrain on that bike. Of course, it has a Rekluse clutch and is easier to ride and I would never (cough, cough) take it on the road.
The person who commented about no rocks in the Dakar needs to read or watch Charley Boorman's 'Race to Dakar'. One of the many obstacles is rocks, rocks, and more rocks.
With this said, check out the www.rallypanam.com
website and look at what was done to those bikes. Very cool. Very fast. I bet that they are fun to ride.