I bought a used luggage system from these very forums and got it installed yesterday. It's the older Zega cases by touratech mounted on the KTM rack. Install was pretty straightforward and easy, just watch out for a few things:
1. It's very easy to shave plastic off of your fender around the grab handle holes where the top mounts.
2. Be careful where the bolts go in at the buddy peg mounts if you use this rack. It took a bit of pushing to line the holes up, and I very nearly cross threaded a bolt on one side.
Other than that, went on super easy! I'm quite happy with my purchase, since it was well below retail. I've also always liked the idea of hard luggage for road trips. Since I've never brought more than a camelback and maybe a bum bag with me on tough trails, I'm not too worried about hard case issues there. It's strange getting used to hearing hard stuff rattling around in these aluminum cases, though. Haha.
Also, everyone knows a thread isn't a thread without pics!