Flatbed synthetic bed boards

[68C30Flatbed]

I have acquired a 68 Chevy C30 Flatbed with rotten planks on the bed. Any reason not to replace them with those synthetic wood resin planks that 'can be worked just like wood'? I figure they will be more durable, never rot, and make loading easier because they are probably more slippery. What about breaking strength? Anybody tried this? Yes, it's heresy to a restorer, but it's practical for someone needing a long term working truck.