Christian,
What would you recommend for a 75kg rider with the same experience as Dave and the same winds who has a 146 x 44 board?
Thanks
That's a MASSIVE board for someone your size. A board this big falls into the light wind category as in less than 15 knots.
The only advantage of such a big board (other than the light wind benefit) is when you're at the very early stages of learning to water start and ride. Once you can ride comfortably in both directions a board this big will slow your progress down in any winds stronger than 15 knots which are typically associated with choppy waters.
Your next board should be at least 10cm shorter, i.e around 132-136cm. Keep your big board for light days it'll come in handy.
At first you will find it difficult with a small board and that's simply due to poor technique and being used to easy starts with such a large board.
Big kites and big boards are always the easy solution for learners but in the long run they slow your progression down and, more importantly they encourage bad habits and poor technique, especially in higher winds.
Christian