I too would give a thumbs up for the Dakar.
I have replaced wheel bearings, SHB, fork seals, chains and sprockets and had to adjust a couple of valve shims (since valves get tighter with time, gently shaving down the shims allows you to adjust them without buying replacements).
I have not had any water pump issues and I like the Dakar so much I just could not see myself selling it. It has been so successful that BMW has brought it back as the G650GS for about $9K.
If BMW would have upgraded the front forks on the G650GS to the F800 forks I would have considered selling the F_Dak and going for the upgrade......but that is not to be.
The service history for a bike will tell you everything you need to know if it is a good buy and..........you likely know this, but check this site for the knowledge base :
http://f650.com/index.php as the F650 thread on ADVRider is mainly about hard core alterations.
Here is a link to pic/documents for my Dakar :
http://s737.photobucket.com/profile/OceanMtnSea
J