mk i haven't used a sail bigger than a 6.4 for about 12 months, and in the last 3 months nothing bigger than a 5.8, how many days have we had more than 15-20 knots in that time? not many and on those days i was on a 5.3m. that aside my board is 125lt
so it is possible to compare a 70kg person on a 5.7 with a 100kg person on a 5.8 because the key is that we are all using freestyle boards (early planing) with 20-30lt more volume than our weight and power wave/freestyle sails, that's the key. For the record, majority of freestyle sailors in SEQ are 75-90 kg using 99-109lt boards with sails between 5.7 and 6.2m
if you want to quote pwa sailors look at tom hartmann, i've been following his advice and setup, the last 3 sessions i've experimented with super long lines which is something he uses. what i found though is the longer lines have reduced my early planing ability, as i am loosing mast foot pressure which is critical to early planing. i know this because of the way the board has been sitting in the water and the amount of wind i have needed to keep planing as well as the response in the lulls.
If you've never sailed my gear i don't see how you could know what it can or can't do or how early it planes or how it responds. next time have a go on my gear, i'm more than keen to let peole jump onto it, as you noticed at wello.
if u use willaus as a benchmark - no body under 100kg has any excuse to not be planing with a sail over 6m on 100litre board in those conditions 
