Hello, and welcome.
We've a member on here who took a Tenere around the world a few years ago - Scottnet, Dazzerrtw is currently in south America having already ridden (2 up !!) over Europe, Asia and North America. In both these cases the bikes have shown to be reliable and a good choice.
We have members who have done other stuff too, from the Heroes Legend Rally to Big Bike Challenges, all of who will testify to the bulletproof nature of these bikes.
They do have some faults and problem areas, but you'll find all the information here somewhere, and once you've dealt with these then you are good to go.....
This might interest you ->
http://www.xt660.com/forumdisplay.php?f=198
There will be an eclectic mix of bikes and riders, best place to sit down with a beer and get some thoughts or ideas, or just look around at the other bikes and see what people have done.