I think Geordie has done what most of the rest of us have done, I used to have 4 boats now I just have the TI. We find it so fun and versatile we never took any of the other boats out so we ended up selling them.
Unfortunately my fun must end for health reasons I have to give up the sport, so now I have to sell my TI as well. I broke my back a few years ago and have very little mobility, kayaking and sailing aggrevates my condition so I have to give it up (maybe I'll take up knitting). It's funny really since I car top my TI, it's not the lifting that gets me (no problem there), it the activity on my back (ie.. turning, twisting, etc), the docs are saying I only have a limited number strokes left in my back (joints are all shot), and advise I give it up.
It's too bad your not close, you would give the Ultimate Tandem Island a good home.
Bottom line though is the TI is the ultimate boat out on the market today (and I believe the most popular), the AI is also nice (as you know), but the TI can do way more and can hold 3-4 adults (and lots of gear (beer), way more than I ever imagined) as long as you don't go crazy with it.
If I had most of the kayaks liquidated that have been accumulating the past 15 years, I'd be all over your TI.