My Nacra 5.2 does have some weatherhelm issues because I haven't figured out a rigging setup that allows me to fulling lower the rudders but still tight enough that they will pop up when I release the line.
I also sail on a friends H16 that used to have a rediculous amount of weatherhelm. He tried all kinds of adjustments and it turned out in the end that the person who set the boat up before he bought it had the rudder arms reversed. When he corrected it, the problem all but disappeared.