I did the install last night. Relatively easy, the hardest part was getting to home depot and ponying up $30 for a hole boring drill bit! The wire taps Givi supplies with the top box are very nice, and from the posts here I think getting the prewired topbox saved me some time. I ran the wire for the lights under the seat and into the space where the trunk latch goes. Probably not ideal, but I didn't want to drill another hole in the bodywork.
I am a little ticked that one of the keys for the box was all bent, but I assume Givi will take care of that.
Overall, a very nice upgrade, and about a 2-3 hour install if you really take your time. Next upgrade is the Baehr intercom! I already have my helmet wired, I just need to get the unit installed!