Hi SupCharlie,
I have the 2017 8'0 x 28 in Carbon but also have been able to compare this with the same board in Starlight.
Firstly let me say that the new 2017 boards are pretty different from previous models, they have much more pulled in noses and tails and also much more refined / thinner rails. This makes the board less stable than previous models but a much improved feel in performance. They seem to generate more speed and transition from rail to rail easier and smoother.
I also have the 2017 8'5 x 29 but the 8'0 x 28 has become my favorite board, however at 79kg it requires more balance and energy to ride this board when there is decent surf.
Differences between constructions:
Weight difference is exactly 1kg, my Carbon is 6.5kg and the Starlite I weighed was 7.5kg
The Starlite probably has more re-enforcing on the rail with the innegra and carbon rail band and also has a re-enforcing stringer through the nose. Overall the quality seems pretty good for the price compared to Carbon.
Difference in riding:
Being slightly heavier the Starlite is just that little less reactive, Carbon boards tend to release from the water quicker as they sit slightly higher which means you can initiate turns quicker. The positive in Starlite is that when there is more water moving or its windier it is less affected.
Couple of pics below with both side by side
Cheers,
Marco