I dunno... maybe it's just me, but the way I only way that I would envision using a Smuggler type rear seat box would be for use on solo day-rides which would be when I wouldn't want a big trunk on the back. Could use it with the side bags if you really needed carrying capacity, but on multi-day extended trips (which are usually 2-up anyway) I'd forgo the smuggler for a real trunk. I guess that's why I could never see spending the coin for the Corbin affair.
That Police trunk looks really promising to me.
And I would never be able to fit either of my dogs in any luggage that would fit onto an FJR (we have 2 labs).