I have had about 30 sibs, including an Aerotec. But I have had 4 Futuras, a Junior, Mk2C FR, Sport and a MK3 FR, the Futuras are a very special boat. Air floor is rock solid, boat is stable, speed tubes give it an even more rigid feel and allow a stupid turn of speed for a sib.
I really think they are the top of the tree, and the new price reflects this.
Downside ? Tubes are not as big as some and they dont have seats on the FR's (You sit of the rather comfy floor
),you dont get oars or oar locks and unless you are at displacement speed you need to have a brave throttle hand to get the best performance. But I think the eye watering new prices areprobably why there are so few about, a MK3 is now close to £5k new !