If you're after an adrenalin hit then buy the Hobie 16. If you are after the most versatile bit of kit on the market then bite the bullet and go the TI.
We've had 14ft and 16ft cats and there is nothing quite like smashing across a bay, flying a hull and pushing the boat to its limits. Pitchpoling and capsizing being all part of the thrill. But they can also be a handful for the inexperienced and it is always a nervous time leaving the mainsheet in the hands of a newbie and trusting they will feed line out before we end up in the drink.
The 16 is a heavy-ish boat, and whilst they can be rigged single handed they are much better suited to having extra hands on deck to help in this regard. So if you like a thrill and often sail with company the 16 footer is a good, (and usually drier) option and you can get a lot of bang for your buck buying second hand.
We have just purchased a TI and love almost everything about it. It is easily set up by one person if need be and this appeals to me as I get time off when others are at work and so often sail alone. It's fantastic for teaching others to sail on and if they were cheaper every Sailability centre in the world would be using them. (When I take friends out I am lucky if I get a go!!! Can't wait til school goes back so I can have some days alone where I get to drive!) We peddle it as a kayak for early morning fishing and then rig it to sail as the wind picks up in the afternoon. By furling the sail we approach jetties and landings with better control and overall we are very impressed.
However it is a wet ride on a choppy day, so factor in windproof clothing in all but the warmest weather. You can take 2 adults and 4 kids as per the youtube video, but in choppy conditions you will all be very wet. Its sailing performance will satisfy most who have sailed other vessels, however it is sluggish downwind due to no boom (others rig their boats differently to improve this) and its upwind performance is more than adequate to chart a course to your favourite picnic spot or waterside cafe! But there are trade offs and one is that the boat is powered in such a way that it is almost impossible to capsize and so whilst it's fantastic for teaching and an outstanding boat all round, one thing I do miss is the adrenalin hit from the sheer speed of the 16.
Price wise, even 2nd hand they are an expensive toy, but so far we have few regrets and hope to keep it in the stable for many years to come. More than 2 cents worth of my opinion I realise but hope it helps.
PS Local surfer here had his butt chewed by a shark this week so if I drag half a tuna in the right location I may be able to up the anti in the adrenalin stakes!