I've talked with the trailer experts around here, and while they think it's a good idea, they recommend tighter spacing on the crossmembers since the synthetic boards aren't as stiff.
But, I still plan to do the change on my 16ft flatbed trailer when I need it refloored for the 3rd time. A few more pieces of angle iron will be a drop in the bucket compared to the price of the synthetic boards.
SSOW
