just a quick bump for closure.
I've decided to go with a starboard ultrasonic rather than a formula. I was out in a southerly today with my 7.0 retro and I was nice and comfortable. I tried my 8.2 earlier on and I wasn't really enoying it. I was watching the formula guys and they looked to be running 10 and 11 metre sails. that's not really my cup of tea sorry guys.
I love the upwind power of the formula's but I should of remembered that performance like that is going to come with a trade off. An ultrasonic with a 60 cm fin will satisfy my upwind needs just fine I think

The ultra sonic was a narrow winner for me over the JP super lightwind. In the end it came down to the tail width and the slightly narrower tail of the starboard suits me a little better I think.
Happy sailing fellas!