I just posted to a similar topic, but let me respond to Lampi. For the most part, I couldn't agree more. After taking my 8.0 Retro out on an F-Type 148 with a 66cm fin, I found I could plane VERY early. I do have a 9.8 V8 and 70cm fin I use when the wind is at its lightest.
I will be doing more testing between these two setups. I was surprised how well the 8.0 and the FType did and I want to see how much I gain by using a 9.8. If I can get out there with less sail, when I'm out of shape, my back and forearms would be happier.
I am going to buy a tandem windsurfer for the lightest of winds. My wife and I will be able to sail together and enjoy the day. It will sort of be like going canoing. I also have resurrected an old Windsurfer Classic. I can put the 8.0 Retro on that and sail. I have found that it is a blast to go out on!
On the subject of kiting, I want to resist picking up another sport. It keeps the funds for windsurfing more available.
Here is the text from my other post on this subject...
I'm 140-145 pounds.
My current lightwind gear is an F-Type 148 and a 9.8 V8. My next smaller sail is a 8.0 Retro. When sailing with heavier sailors (180-200 pounds), I find they go to a 10.6 V8 and a formula board when I'm on my 9.8 V8 and FT148.
The other week, I was using my 8.0 Retro and an iSonic 105 (stock 40cm fin) when the winds were strong enough for it. A friend was on his formula board with a 10.6. He definitely planed earlier than me, but it wasn't by much. I was surprised how close I was to keeping up with him. I should have been on my 9.8 with my F-Type 148, but I wanted to test the low-wind tolerances of my Retro and iSonic combination.
I put a 66cm fin on my F-Type after he packed up and found the 8.0 Retro to be amazing in light winds (I rigged it to the numbers). I use a 70cm fin when I rig the 9.8 V8, by the way.
Here's a picture of me that afternoon with the 8.0 Retro and an F-Type 148. You can see from the water that there wasn't much wind.