I will only state the obvious since my lunch break is almost over and my boss read's the forum. Nac5.2 has daggerboard and the Prindle and Hobie do not. Generally a boat with boards doesnt have as much free space on the deck to sit. The 5.2 will also have more adjustment than a Hobie or Prindle because it's equipped with a mast rotation control. The 5.2 is longer therefore it can theoretically go a little faster than the others due to the waterline.
Since this is your first cat and you will be doing some solo sailing i would suggest you start with a Hobie,Prindle,Nacra 16 footer or 5.0 meter boat. I say this for several reasons...First of all they will be slightly faster to rig (less parts), you can right the boat by yourself easily, less adjustment to worry about, less parts to forget in your garage (done it), very easy to find parts for second hand, etc. I started with a P16 and really loved that boat. The prindle handled all the conditions i put it through very well. Rigging the boat was a peice of cake. I then moved onto a Nacra 5.0 and it was even easier to rig than the prindle(no boom) and seemed to be a little faster. Now i have moved up to a 5.2 with a pentex square top and spin but will not take it out until Friday. I really liked the Nacra 5.0 the best because of its ease..I could set it up and be on the water in under 15 minutes. My opinion is to start with a easy boat and work your way up. Im not saying that all the adjustment on the 5.2 isnt a good thing, but when your new its nice to focus on the simple things and get confident in your skills before you move on to all of the adjustment that a 5.2 or similar has. Just my $.02 cents since ive had all the boats you mentioned.