Yours is a difficult post to reply to because the boats are so different. I have the older AI, which may not be as fast as the new one, but what are we talking? 10% or less difference? I also have a Weta and have over 1000 hours on it now.
At any rate, it all comes down to what you want to do. You just think the Weta was fun... wait until the wind gets into the mid to upper teens and hang on. It turns (spins) on a dime, has a wide operating range and accelerates like mad. It's very capable and the fun factor is extremely high.
But, I don't like it in single digit winds. Spoiled maybe, but it's really only fun once the wind gets cranking. At least for me.
On the other hand, the AI and TI while not as fast, are very comfortable, better for fishing, camping, long distance sailing, etc., and with the mirage drive you're never out of luck wind-wise.
The AI and TI do move pretty well, better than most small monohulls, and because you're right down on the water you get a good sensation of speed plus plenty of water and spray in your face. For all-around use they're just darn tough to beat. Extremely versatile. So many things you can do with them. If I could only have one, it'd be an Island.
Here's my latest video taken this past week with a girl who was recently given a monohull and is learning to sail. It was really, really hot and the wind not entirely dependable, so with the two to choose from, we took the TI so we could motivate no matter what . And... she has also been on the Weta (that video is also linked here) and she said that she thinks the TI is more fun. You judge for yourself.
https://www.youtube.com/watch?v=9Djq2uaZ724https://www.youtube.com/watch?v=fzW-rBt8iYM