good replies all - but I think you have to look at the history of the development of these boats to consider your use and purchase. If I recall from the Worrell and Alter books: the 16 was designed for a crew of 2. Hobie envisioned this as a boat for his vision of the perfect California couple with a dude at 130 to 170 lbs and a babe at 110 to 130 lbs. Standard rigging on the 16 was a single trap for the crew. The boat was built for performance and righting ability with this in mind. The 14 came about directly as a challenge to the (still) largest fleet in the world (besides the Optimist Pram) -the Sunfish. He wanted to bring a lot more fun to the single young sailor in the under 150 lb category. Of course, the 14 turbo soon followed because - well, if speed is good, then more speed is better. It was a balls-out fast challenge to the Sunfish, but never really caught on. It's just a different breed of boat. The 18 fits in here somewhere but I am not sure where - and then the 18 with wing seats. Dual trap was standard. It is still an AWESOME craft but you don't want to wash the sails if you are out single handed with less than 340 lbs to get it back up (if memory serves). Then the 17 - single sail, one line control, one trap with wings for leverage designed for the single handed sailor of up to 220 lbs and then the 17Sport with a jib - ala' H14 turbo redux.
In essence - the 17 is a single hander. In reality, it depends on how hard she's blowing. I have had 3 adults trying to pin mine down- funny thing- there was not another boat on the entire lake that day. I read about the tornado warnings the next day