BelScorpio, I am sure Formula came to us as divine intervention, yet I am just still striving to have a bit of the slalom feeling in the 8-15 knots range. Therefore, many like MarkH and others clearly recommended the iS150 which will surely plan earlier that the iS144 and everyone agreed! Sounds to me that below 8 knots is Formula land. I think that discussion was completed! Noone recommended the Futura 155 (with 161 ltrs volume) in Wooud Carbon. As PG argued Weight is secondary to Width. Given the Formula arguments, WIDTH RULES, thus the WOOD iS150's ~94 cm will definitely plan quicker than WC iS144 and the WC Futura 155's (both 85 cm)!
In summary, and according to the discussion so far, it makes NO SENSE to buy a large volume Wood Carbon board at all (unless it is a Wave/Freestyle board). The WOOD version will be max. 0,5 knots slower, which for the skillset of most of us it's imperceptible!
In low winds you are not interested in fast response - rather you are planning based on large fins, sails and wide boards. As the Team has not intercepted I will transfer the question of the WC <> Wood in >120L boards in another thread...