Yeah around 2004, I don't remember there being a sudden change more like an evolution. I know in 2006 boards starting getting faster rocker lines and becoming shorter and wider. I've got a JP 2005 radical wave 74l which I am pretty happy with, but last year I tried out a 2006 Radical Wave 69l and that was awesome. It was more like a surfboard than a windsurfer. This was in Egypt so never got to try it wave conditions more like large swell, but I reckon it would be great in the waves. So when I get a bit more $$ together I will trade in my JP and get a 69l Rad. wave and an 83l Real World wave.
Haven't sailed a starboard for a while, but my mate swears by them and by Severne sails. He also reckons I'm pony for sailing JP & NP....