I did not know that about the AI, I know on my TI I've had 5-6 people out sailing several times. I took a family out for their first ride on a sailboat out in Florida bay near Islamorada (a mom, dad, two tweens (10 and 12), and myself, (around 800 lbs) and the boat actually sailed nicely, I even had the spinnaker up and we got up to around 8-10 mph. Of course the water was shallow, and we stayed close to shore. I always carry 6 PFD's on board because we often go out just off shore snorkeling (usually off Higgs beach or tank Island in KW). At that weight the mirage wells were full of water and the water level was about 1-1.5 inches below the center hatch. I figured when we came in the hull would be full of water, but it wasn't bad (maybe a little more than a quart if I remember correctly), but we were in and out all day going out snorkeling, and sailing (people taking turns going out), getting equipment in and out of all the hatches etc. We were there for a week and moored just off shore for the duration (when we weren't sailing). Here is a pic of my TI moored for the night.
I just assumed all of Hobies boats were similar.