Thanks for all the responses guys!
Ive now heard elsewhere that the 70 has a little extra "McK/Tiesda fairy dust" in it compared to the 75, and even for an intermediate 82kg DTL-er like myself it might be more applicable as a higher wind board than the 75 - esp if im keeping the 80.
(btw - had a really fun session on the 80 again yesterday, it was light cross-on so used a 25cm drake rather than the 23 with my 5.8 - really great 1 hr session jumping off the waist high waves in the rare uk sunshine....still didnt pull the trigger on them loops though :-I )
Regarding the 90 v 100 - at 81 kg (weighed myself this morning - yeah - ive lost 1 kg!), what would the 100 realistically offer me over the 90...Ive noticed from the specs its looks look a similar planshape / width, so im guessing the 100 is essentially a thicker / corkier version which although adding to the feel of bouyancy will make it a LOT more cumbersome riding at my weight? Is it fair to say that the 100 is more aimed at someone antoine's weight ie 95Kg and if im looking for a schlogging / riding tool then 90 would be nearer the money?
Aggghhh - i think im talking myself into a 70+80+? kinda quiver when ive been trying to get back to just two boards!