Firstly i want to say that i have spent the last two weeks reading this forum, and i have learned HEAPS of things, so thanks for all the awesome responses.
After using an F2 Lightning long board for the last few years, becoming very confident on that, i have bought a Hypersonic 111. After two sessions i am really starting to enjoy it, planing relatively easily and having no real problems getting into the harness lines and footstraps.
The thing i have noticed is that coming off the water, my forearms are burning like never before. Im using the same 7m sail, mast and boom as i was on the F2, and haven't moved my harness lines from where they were, but for some reason it feels like the harness lines are too short and im supporting myself too much on my arms.
any ideas? time to try some longer harness lines maybe?