Finally installed the cruise control this weekend. Some of it was a real pain (attaching the CC cable to the throttle body cam), and it did take more time that I thought it would, but the end result is very much worth it. The operation is very smooth, and it all works as advertised.
The general procedure for wiring one up to an FJR1300 is found here:
http://www.fjr1300.info/howto/audiovox.html
The wiring is surprisingly easy, and the whole install could be accomplished on almost any bike, provided that room for the sizeable servo unit can be found.
I used a $2.50 Fram fuel filter as a vacuum boost container, inline with the vacuum line hooked to cylinder 4. I also routed all the control pad wiring down the middle front fairing spar, as shown in the pic, and hot-glued the control pad to the clutch reservoir and handlebar, also shown in the pic.
So, $95 or so, and about ten hours later, it's a done deal.