I have just purchased an 96 XTZ 660 with 22000km on the clock in very good condition. Previously I owned an Africa Twin, but with today traffic, moto accidents and police on the road, I'm every day more off road. XTZ is beeter off road than AT just so much as it is worse on the road but this is just waht I need.
The first thing I did to improove off road capability is to change the handelbar with one "more normal", because the original is at least for me very strange curved. I also raised it up for 2,5cm and put on some Acerbis handguards. Then I've put on off road tyres (Mitas E09), remove the rubbers on the pads and remove the pads for the passenger.
Things to do are also to change the silencer and I have just ordered some WP progressive springs for front forks. That is it for me. It will be ready for Tunisian desert.