I won't hide that I'm not a fan of plastic wood substitutes, for all sorts of perfectly logical (nor egocentric) reasons. But... I can see some people wanting to use these-- provided they're used properly.
Don't bed it down to the cabin sole. Just make boards or grids out of it and set them in place. There's not much that adheres to it, as far as marine bedding compounds; and household (HoDePo) products won't hold up to the marine environment. This is true with all forms of household materials and adhesives. The number-one reason for rotten cabin soles is plywood going bad from moisture trapped between it and whatever's on top of it (carpet, parquet floor, etc.). If you're creative you can come up with very nice removable panels or grids for the cabin and cockpit soles and be able to take them out to clean and during storage.
As to durability, the UV will eat it like gravy. I'd give it five-six years, tops, before it begins to look bad. I grew up working with and around contractors at the NJ Shore who claimed 'Wood is good but vinyl is final'. Well; they're wrong; only a vinyl-siding salesman would say that. Vinyl siding is chalky paste in about 15 years. I'd venture the same timeframe for these polypropylene fake-wood products as well (including Starboard, which both loves mold and faints under UV).
The best thing about wood is that, though it tends to need refinishing more often than plastic does, it can in fact BE refinished, mended, painted, bedded permanently, and somewhat aesthetically appealing into the bargain.
