I used to own a Nacra 5.7 and it is a wonderfull beach cat for cruising and for drag racing

It is also very save, no daggerboards like the TheMightyHobie18 and a boomless main. The cat is very resistant tom pitchpole as well and it has alot of buoyancy.

Drawback: Very difficult to right. It has a long and heavy mast like most of the cats of that era but since it's boardless, there is almost no leverage.
Also is is more difficult to tack but you will get the hang for it.

If you go with a Nacra 5.7, you should buy a righting kit like a waterbag or a righting bar.

I also sailed with a Hobie16 and they are very practical catamaran. They are a breeze to set up, much faster to set up than other cats. They will not handle the extra weight that well but they will handle it anyways. I remember this crazy sailing session in the OBX where we had over 450lbs on the wire and over 600lbs on board. The boat was so wet that we had to wear googles to see where we were heading.

Charles Leblanc
Nacra 5.2