Hi Instigator!
If you haven't already, check out the discussion of adding a jib to a Hobie Outfitter on this link:
http://www.hobiecat.com/community/viewt ... highlight=
Yes it does improve sailing (at least in low wind conditions), and the way the jib was attached, it would probably work for an inflatable, as there wasn't any drilling required for rigging the sail, as long as you can use figure 9s on your shrouds.
After one test run, I wouldn't sail in low winds without it...and it wouldn't hurt to add the cleverly named boombat for downwind performance.
-Tracker-